Rad-140 (Testolone)

A short introduction

Most people who have worked with me know that I approach SARMs with a healthy dose of skepticism. The main reason is simple - these are relatively new compounds, and the amount of solid clinical research in humans is still limited.

While writing this article, I reviewed the available scientific publications on RAD-140, along with hundreds of user reports from forums and specialist groups. More importantly - over the past few years, I have had the chance to personally guide a dozen or so people through RAD-140 cycles, which allows me to look at this subject not only from a theoretical perspective, but also from a practical one.

I wanted this material to be as complete, realistic, and honest as possible. And although I stuck to the facts and kept a neutral tone while writing it, after reading the finished version I realized that it might come across as if I were praising RAD-140.

That is why I decided to add this short introduction and clear up any doubts. This is not a sponsored article. My goal was not to promote the compound, but to present its potential, effects, and risks as realistically as possible.

What is RAD-140 (Testolone)?

RAD-140 is one of the better-known SARMs and has more research behind it than many similar compounds. It is a selective androgen receptor modulator, or SARM. It was developed by Radius Health to treat conditions associated with muscle wasting, such as sarcopenia, breast cancer, and osteoporosis.

Unlike classic anabolic-androgenic steroids, such as testosterone or nandrolone, RAD-140 works selectively - it binds mainly to androgen receptors in muscle and bone tissue, while having much lower activity in other tissues, such as the prostate or skin. In theory, this reduces the risk of side effects while still producing strong anabolic effects.

History and purpose of development

RAD-140 was first described in 2010. From the very beginning, the goal was to develop a compound that:

• increases muscle mass and strength without the classic side effects of steroids,
• does not convert to estrogen,
• does not cause prostate enlargement,
• has neuroprotective effects, especially in the context of Alzheimer's disease.

In animal studies, RAD-140 produced strong anabolic effects without the same prostate stimulation seen with testosterone. That is one of the reasons it became interesting for both researchers and athletes.

How RAD-140 works

RAD-140 is a selective androgen receptor modulator (SARM) that works by binding to androgen receptors in the body - in a similar way to testosterone and other anabolic steroids. The key difference is that RAD-140 does this selectively, activating receptors mainly in muscle and bone tissue, while largely bypassing other androgen-sensitive tissues, such as the prostate or skin.

Androgen receptors - what they are and where they are found

Androgen receptors (ARs) are proteins found in, among other places:

• muscle tissue,
• bone,
• the brain,
• the liver,
• the prostate gland.

When these receptors are activated, for example by testosterone, a series of anabolic reactions follows: protein synthesis, muscle growth, improved bone density, as well as effects on libido, mood, and metabolism.

RAD-140 is designed to target mainly the receptors responsible for anabolic effects, while bypassing those linked to unwanted side effects, such as prostate enlargement.

Selective action - the key advantage

Testosterone acts wherever androgen receptors are present - without exception. RAD-140 works selectively because its molecular structure allows it to activate receptors mainly in selected tissues:

• in muscle - strong activation and stimulation of protein synthesis,
• in bone - protection against loss of density,
• in the brain - neuroprotective effects,
• in the prostate - virtually no activation.

This selectivity is why RAD-140:

• does not cause gynecomastia,
• does not cause water retention,
• does not increase the risk of androgenic hair loss,
• is less likely to cause acne or excessive skin oiliness.

Differences compared with testosterone and other SARMs

RAD-140 is one of the most potent anabolic SARMs currently available on the market. Its effects are often compared to testosterone at clinical doses, but without the same level of androgenic side effects.

Benefits of RAD-140

RAD-140 is regarded as one of the strongest SARMs on the market - and for good reason. The effects reported by users and supported by preclinical research put it close to testosterone in terms of muscle mass and strength gains, but without some of the typical side effects.

Muscle mass gains

RAD-140 strongly stimulates protein synthesis and muscle hypertrophy. In animal studies, it contributed to rapid increases in lean body mass, at doses up to 70-80% lower than those required with testosterone to achieve a comparable anabolic effect.

In practice:

• some users report gaining 2-5 kg of body weight as early as 2-3 weeks in, although it should be noted that this result is rare and may include not only lean muscle mass, but also glycogen and intracellular water,
• no subcutaneous water retention - most of the gain comes from muscle, glycogen, and intracellular water, giving a fuller look without the bloated appearance,
• it works well both during a bulk and body recomposition.

Strength increases

RAD-140 increases androgen receptor density in muscle tissue, which translates into strength gains without necessarily increasing body weight at the same rate.

Users commonly notice:

• improved performance in the main lifts, such as the deadlift, squat, and bench press,
• better recovery between sets and training sessions,
• greater explosiveness and better control under load.

Muscle preservation during a cut

RAD-140 works very well during a calorie deficit. When energy intake is reduced, it has an anti-catabolic effect - protecting muscle tissue from breakdown.

Most people choose RAD-140 for:

• competitors preparing for a show,
• people aiming to get below 10% body fat,
• anyone who does not want to lose the gains built during a bulk.

Potential neuroprotective effects

One of RAD-140's distinctive properties, and one that sets it apart from other SARMs, is its protective effect on the brain.

Preclinical studies have shown:

• protective activity against β-amyloid toxicity, a factor involved in the development of Alzheimer's disease,
• improvements in memory and cognitive function in animals,
• therapeutic potential in neurodegenerative conditions.

Although solid clinical data in humans is still lacking, many users report improved focus and more stable mood while using RAD-140.

Bone density

Androgen receptors are also present in bone tissue. Their activation stimulates new bone formation and slows resorption, meaning bone breakdown.

RAD-140 may:

• improve bone mineral density,
• support bone health in osteopenia and osteoporosis,
• reduce the risk of fractures in physically active individuals.

Potential side effects of RAD-140

Although RAD-140 is considered a safer alternative to steroids, it is not a compound free of side effects. Its selective action reduces the risk of complications, but does not eliminate it completely. Specific adverse effects can appear, especially with longer cycles or higher doses.

Testosterone suppression

The most commonly reported side effect of RAD-140 is a reduction in natural testosterone production.

• In studies and user reports, drops in LH and FSH can be seen as early as 3-4 weeks in. Symptoms may include reduced libido, lower energy, erectile problems, and brain fog.
• After the cycle, proper PCT (post-cycle therapy) is usually needed, especially if the cycle lasted more than 6 weeks or the dose exceeded 10 mg per day.

Suppression is less aggressive than with steroids, but it can still be noticeable, especially in people who are hormonally sensitive.

Liver toxicity - myth or fact?

RAD-140 is not a classically hepatotoxic compound like Dianabol or Superdrol, but it is not completely neutral for the liver either. There are cases where users report elevated liver enzymes (ALT, AST), especially with longer cycles, higher doses, or poor cycle support.

Why can liver markers increase?

• Hepatic metabolism: RAD-140 is metabolized by cytochrome P450 enzymes, mainly CYP3A4, which places additional strain on the liver, especially with prolonged use.
• Enzymatic induction: in some people, there is a temporary increase in ALT, AST, and ALP activity, most often without any real clinical symptoms.
• General metabolic load: increased protein synthesis, nitrogen metabolism, and energy turnover can affect liver function.
• User-related mistakes: alcohol consumption, combining RAD-140 with toxic substances such as YK-11 or prohormones - compounds that act as precursors to anabolic steroids and convert into active hormones in the body - poor hydration, and deficiencies in B vitamins or choline.

Blood work monitoring (ALT, AST, ALP, bilirubin, GGT) is recommended at least once in the middle of the cycle.

What values are we looking at?

• ALT/AST may rise to 60-80 U/L, which can still be acceptable,
• levels above 100 U/L suggest that something is not right,
• bilirubin rarely increases, but if it does, the cycle should be stopped immediately.

Basic protection:

• at least 3 liters of water per day,
• avoiding alcohol,
• regular sleep and a diet free of processed junk.

Supportive supplementation:

• NAC (N-acetylcysteine): 600-1200 mg per day
• Silymarin: 300-600 mg per day (milk thistle)
• TUDCA: 250-500 mg per day (the strongest option if ALT exceeds 100 U/L)
• Omega-3, choline, vitamin B6, and inositol - support fat metabolism and detoxification

RAD-140 and cholesterol / lipid profile

RAD-140 can worsen the lipid profile, mainly by lowering HDL, the fraction commonly known as "good cholesterol." This effect is not unique to RAD-140. A similar pattern has been observed with other oral SARMs and anabolic-androgenic steroids, because androgen receptor activation affects lipid metabolism in the liver.

The most common problem is a drop in HDL. LDL may remain relatively unchanged or increase, especially when the cycle is long, the diet is high in trans fats and saturated fats, and estrogen levels drop due to suppression of the hormonal axis. In men, estradiol is not a "useless hormone." E2 that is too low worsens the lipid profile, joint recovery, libido, and overall well-being.

I covered how to take care of your lipid profile in a separate complete article: Lipid Panel on an AAS Cycle.

RAD-140 and blood pressure and hematocrit

RAD-140 alone should not raise blood pressure. It does not aromatize, does not increase estradiol, and with testosterone suppression, estradiol may even decline over time. It also does not cause water and sodium retention in the way some anabolic-androgenic steroids do. If blood pressure rises during a RAD-140 cycle, I would look for the cause elsewhere: training intensity that is too high, insufficient fluid intake, stimulants, poor sleep, or combining RAD-140 with other compounds, for example testosterone.

In my own practice, I have not seen a single case or credible report of RAD-140 alone raising hematocrit. If hematocrit increases during a cycle, it is more often due to stacking it with anabolic-androgenic steroids, dehydration, or other factors unrelated to this SARM.

Libido, acne, mood swings

Although RAD-140 does not convert to DHT, its androgenic activity can still affect:

• acne, especially in people prone to it,
• mood, including aggression, irritability, and low mood after the cycle,
• libido, which may increase during the cycle and then drop sharply after it ends due to suppression.

These effects are not common, but they are worth keeping in mind.

Does RAD-140 cause gynecomastia?

RAD-140 itself does not aromatize to estrogen, so theoretically it cannot cause gynecomastia. In practice, however:

• some people report a mild increase in estrogen, most likely as a compensatory effect,
• with longer cycles, conversion of residual testosterone can occur,
• increased sensitivity of estrogen receptors may also play a role.

For anyone with a history of gynecomastia, it is worth having a drug that blocks estrogen receptors on hand, such as tamoxifen, even if the risk is minimal.

RAD-140 and hormonal profile

As a potent SARM, RAD-140 directly affects the hypothalamic-pituitary-gonadal (HPG) axis. Its activity can suppress the natural production of sex hormones, even though it does not convert to estrogen or DHT.

How does it affect LH and FSH?

LH (luteinizing hormone) and FSH (follicle-stimulating hormone) are two key pituitary hormones that stimulate the testes to produce testosterone and support spermatogenesis.

• RAD-140 acts as an exogenous androgen receptor agonist,
• the body interprets this as an excess of androgens and suppresses LH and FSH production,
• the result is a drop in natural testosterone production and potentially reduced fertility.

Based on studies, such as the RAD140 study by Radius Health, and user reports:

• drops in LH and FSH can be noticeable as early as 2 weeks in,
• the higher the dose and the longer the cycle, the deeper the suppression,
• at doses of 10 mg per day or more, near-complete suppression of LH is possible.

Estradiol - what happens without aromatization?

RAD-140 does not convert to estrogen. Yet some users report an increase in estradiol levels. How is that possible?

• Increased aromatase activity in response to disrupted hormonal balance.
• Conversion of residual testosterone to estrogen - if natural testosterone is still present in the early phase of the cycle, it can aromatize to estradiol, especially when hormonal balance is off and aromatase remains active.
• Increased estrogen receptor sensitivity - the body may respond more strongly even to low estrogen levels. As a result, symptoms typically associated with excess E2, such as nipple sensitivity and water retention, can appear even when estradiol levels are physiologically low.

In practice, it is worth:

• monitoring E2 (estradiol) levels during longer cycles,
• not using aromatase inhibitors preemptively, unless symptoms clearly point to hyperestrogenism. The best approach is to get estradiol tested in a lab.

Prolactin - an often overlooked factor

Although RAD-140 does not act directly on dopamine receptors or affect estrogen in the classic sense:

• a drop in testosterone can disrupt the T/E2 ratio, meaning the testosterone-to-estradiol ratio becomes too low. When T/E2 falls, the risk of elevated prolactin increases because the body can no longer maintain the right balance between androgens and estrogens, which disrupts control over PRL secretion,
• some people see an increase in PRL, especially after the cycle. The mechanism behind the T/E2 ratio's effect on prolactin is explained below,
• the effects may include reduced libido, erectile issues, brain fog, and low mood.

Recommendation: if symptoms appear, run a hormone panel: PRL, E2, LH, FSH, total and free testosterone.

Why does the T/E2 ratio affect prolactin?

Prolactin is inhibited by dopamine, and its levels depend indirectly on the balance between androgens (testosterone) and estrogens (estradiol).

• When the T/E2 ratio drops, meaning testosterone is low while E2 is relatively higher, the body loses hormonal balance.
• Estrogens can stimulate prolactin secretion, especially when they are not balanced by androgens.
• On top of that, low testosterone means weaker dopaminergic activity, which worsens control over PRL.

As a result, even with "normal" E2 levels, if testosterone drops too far, prolactin can rise, causing problems with libido, erections, and mood.

The optimal T/E2 ratio is generally considered to be 15:1 to 25:1. If it approaches 10:1 or lower, the risk of hyperprolactinemia increases.

RAD-140 vs. testosterone vs. LGD-4033

When and how should PCT be used?

If the RAD-140 cycle lasts longer than 6 weeks or the dose exceeds 10 mg, PCT is mandatory. Otherwise, the risk of low testosterone after the cycle is very high.

Common PCT options:

• Tamoxifen (Nolvadex): 20-40 mg for 4 weeks,
• Clomid: 25-50 mg for 4 weeks,
• Enclomiphene - a modern alternative to Clomid with fewer side effects.

Natural testosterone boosters can support the process, but they will not be enough on their own when HPG axis suppression is significant.

For more on post-cycle therapy, see the dedicated article: PCT - Post-Cycle Therapy.

RAD-140 dosage and cycle length

Despite its potency, RAD-140 does not require high doses to produce noticeable effects. Going beyond reasonable ranges does not improve results - it only increases the risk of side effects, especially suppression of testosterone production.

Optimal RAD-140 dosage

Dosage depends on the user's experience, the goal of the cycle, and individual tolerance.

For beginners:

• 5-10 mg per day for 6-8 weeks,
• minimal suppression, noticeable gains in strength and muscle mass,
• a good option for a first experience with a SARM.

I recommend running PCT either way.

For intermediate users:

• 10-15 mg per day for 8-10 weeks,
• stronger anabolic effect, higher risk of suppression,
• PCT is required after the cycle.

For advanced users (optional):

• 15-20 mg per day for 10-12 weeks,
• an aggressive protocol - only with very good tolerance,
• higher risk of LH/FSH suppression, meaning PCT is necessary, and possible E2 fluctuations.

Going above 20 mg per day is not recommended. The benefits are marginal, while side effects increase exponentially.

Cycle length - how many weeks?

The recommended cycle length is 6-10 weeks, depending on the dose and goal:

• 6 weeks: recomposition and minimization of side effects,
• 8 weeks: a balance between results and safety,
• 10-12 weeks: maximization of effects, but PCT is required.

With longer cycles, it is worth doing follow-up blood work after week 6: testosterone, LH, FSH, E2, prolactin, ALT, and AST.

Tapering - is it worth it?

With RAD-140, tapering, meaning gradually reducing the dose toward the end of the cycle, is not necessary, but it can make the transition into PCT smoother:

• final week: reduce from 15 mg to 10 mg, then to 5 mg,
• this acts as a "soft landing" for the hormonal system.

It is not mandatory, but it may reduce the shock to the HPTA axis.

Example RAD-140 protocols

Beginner (recomposition):

• Weeks 1-8: RAD-140 10 mg per day
• PCT: tamoxifen 20 mg for 4 weeks

Muscle mass (intermediate):

• Weeks 1-10:
  • RAD-140 15 mg per day
  • MK-677 10-20 mg at night (optional)
• PCT: clomid 25 mg + tamoxifen 20 mg for 4 weeks, or clomid 50 mg alone

Aggressive protocol (advanced):

• Weeks 1-12: RAD-140 20 mg per day
• Weeks 11-12: reduce to 10 mg
• PCT: tamoxifen 40/40/20/20 mg over 4 weeks

Remember that these are only examples, not ready-made protocols.

Forms of RAD-140 administration

RAD-140 is most commonly available in oral form - either as a liquid solution or in capsules. Both forms have their advantages and disadvantages, and the choice mainly depends on the manufacturer, dosing accuracy, and user preference.

Oral solutions (liquids)

This is the most common form on the underground market and in research chemical shops.

Advantages:

• easy and quick dosing with a pipette,
• allows for very precise dose adjustment, for example 7.5 mg,
• may absorb faster.

Disadvantages:

• bitter taste, often very unpleasant,
• variable solvent quality, sometimes alcohol, sometimes MCT oil,
• less convenient to transport due to the risk of spilling or confiscation.

Note: always shake the bottle well before use, as the compound may settle.

Capsules and tablets

Encapsulated versions are becoming more common. They are more user-friendly and convenient.

Advantages:

• no taste,
• easy storage and dosing,
• lower risk of dosing mistakes.

Disadvantages:

• no option to split the dose,
• it is not always clear what is inside, especially with products without certificates,
• less widely available than liquids.

Legal status of RAD-140

• USA: banned by the FDA from being sold as a supplement, but available as a research chemical,
• Canada and Australia: controlled substance,
• WADA: prohibited in sport and listed as a banned doping agent.

Using RAD-140 for athletic purposes is prohibited in professional competition, but it is not a criminal offense if the product comes from a legal source and is used "for research purposes."

RAD-140 and women

RAD-140, as a strong SARM, attracts considerable interest among women who train for strength, fitness, or physique goals. However, because of its strong anabolic and partially androgenic activity, this topic requires a very careful approach.

Can women use RAD-140?

Yes - but only with appropriate dosing and a clear understanding of the risk of virilization. RAD-140 is not approved for medical use in women, so using it for athletic purposes is entirely off-label and comes with potential side effects.

Risk of virilization

RAD-140 does not convert to DHT, but it still activates androgen receptors in many tissues. This means it can lead to symptoms of virilization:

• voice deepening,
• excessive hair growth on the face, abdomen, or back,
• thinning hair on the scalp, meaning androgenic alopecia,
• menstrual cycle disruption,
• clitoral enlargement.

The risk depends on the dose, cycle length, and individual sensitivity.

Recommended doses and cycle length for women

Minimalism is key. Most women exceed safe thresholds when using doses intended for men, which is why microdosing should be used.

Safe starting protocol for women:

• 2.5 mg RAD-140 per day for 4-6 weeks,
• monitoring for signs of androgenization from week 2 onward,
• if any problems appear, stop immediately.

Maximum reasonable dose:

• 5 mg per day, for no longer than 6-8 weeks,
• only for women with previous SARM experience, such as LGD-4033 or Ostarine.

Do women need PCT?

Women do not have a hypothalamic-pituitary-testicular axis in the male sense, but their hormonal system can still become dysregulated. Possible effects include:

• menstrual cycle disruption,
• mood swings,
• reduced libido.

In most cases, the body returns to homeostasis on its own within a few weeks after discontinuation. PCT is not necessary, but natural support can be used, such as ashwagandha, DIM, vitamin B6, or adaptogens.

RAD-140 vs. other compounds for women

RAD-140 in scientific research

Although RAD-140 (Testolone) has been available on the market for years, its status in research and medicine remains experimental. Still, there is solid preclinical data and preliminary clinical trial data showing the potential of this compound in treating wasting-related conditions.

Preclinical studies (animal models)

In studies conducted by Radius Health, RAD-140 showed:

• strong anabolic activity in muscle tissue,
• no stimulation of androgen-dependent tissues, such as the prostate,
• improved bone mineral density,
• neuroprotective effects - protecting neurons against β-amyloid toxicity, which is important in the context of Alzheimer's disease.

Source:

https://www.ncbi.nlm.nih.gov/pubmed/29126313 - "RAD140, a SARM, is neuroprotective in cultured neurons and in animal models of neurodegeneration."

Clinical trials - current status

RAD-140 was included in a Phase I clinical trial:

• Title: A Phase 1 Study of RAD140 in Patients With Hormone Receptor Positive Breast Cancer
• Sponsor: Radius Health
• Study population: women with ER+/HER2- breast cancer
• Objective: to evaluate the safety, tolerability, pharmacokinetics, and efficacy of RAD-140 in the treatment of estrogen-dependent cancers

Findings:

• RAD-140 was well tolerated at doses up to 150 mg per day,
• partial disease stabilization was observed in some patients,
• no strong side effects typical of androgen therapies were reported.

Source: ClinicalTrials.gov - NCT02652864

Neuroprotective potential

RAD-140 has also been studied for its effects on neurons and brain tissue. Studies on neurons and animal models suggest that:

• RAD-140 protects against β-amyloid toxicity,
• it may support neuronal regeneration after injury,
• it acts similarly to testosterone, but without conversion to estrogen.

This makes RAD-140 a potential compound for supporting therapy in neurodegenerative diseases, although it is still far from clinical use.

Potential use in osteoporosis and sarcopenia

Like other SARMs, RAD-140 may support:

• treatment of muscle wasting, meaning sarcopenia,
• improved bone density in older people or those with osteoporosis,
• recovery after injuries and orthopedic procedures.

For this reason, SARMs, including RAD-140, are being studied as an alternative to TRT or estrogen therapy, especially in older people, where classic steroids carry too much risk.

No FDA approval

At the time of writing, RAD-140 has not been approved by the FDA either as a drug or as a supplement. It may legally be used only as a research chemical.

Stacking RAD-140 with other compounds

RAD-140 is very versatile and can be effectively combined with other compounds, including both SARMs and classic anabolic steroids. The choice of combination depends on the goal of the cycle, such as bulking, cutting, or recomposition, as well as the user's experience level and how well they tolerate side effects.

RAD-140 + MK-677 (ibutamoren)

Goal: muscle mass and recovery

• MK-677 increases GH and IGF-1 levels, which supports anabolism and recovery,
• it can also support appetite, sleep, and muscle growth,
• it does not add extra stress to the hormonal system.

Example:

• RAD-140: 10-15 mg per day
• MK-677: 10-25 mg at night
• Cycle: 8-12 weeks

RAD-140 + GW-501516 (Cardarine)

Goal: recomposition, improved endurance, fat loss

• Cardarine increases mitochondrial efficiency and fatty acid oxidation,
• it works very well with RAD-140 during recomposition.

Example:

• RAD-140: 10 mg per day
• GW-501516: 10-20 mg per day, split into 2 doses
• Cycle: 6-8 weeks

RAD-140 + YK-11, S4, or LGD-4033

Goal: maximum hypertrophy and strength

• Stacking RAD-140 with other SARMs requires more caution because it increases the risk of suppression, meaning suppression of natural testosterone production.
• YK-11 acts as a myostatin inhibitor, but it is hepatotoxic.
• S4 can cause visual side effects.
• LGD-4033 is the milder option - synergistic, but without an excessive number of side effects.

Example: RAD-140 + LGD

• RAD-140: 10 mg per day
• LGD-4033: 5 mg per day
• Cycle: 6-8 weeks

RAD-140 + Testosterone

Goal: maximum anabolic effect with hormonal support

• Testosterone acts as the base, supporting libido, mood, and metabolic function.
• RAD-140 adds an extra anabolic effect without aromatization or water retention.

Protocol:

• Testosterone enanthate: 125-250 mg per week, either TRT or a low-dose cycle
• RAD-140: 10-15 mg per day for 8-10 weeks
• Aromatase inhibitor if needed, for example Arimidex 0.25 mg every 3 days, but only if E2 is elevated. Always test estradiol first and do not use an AI without a clear reason.
• After the cycle: PCT or transition to TRT, depending on the goal.

Advantages of this stack:

• preserved libido and sexual function,
• good control over estradiol,
• greater synergy for building muscle mass and strength.

What to avoid when stacking with RAD-140

• Other strong SARMs at high doses, for example YK-11 + S4 + RAD-140, because this creates too much stress for the hormonal system.
• 17α-alkylated oral steroids, such as Winstrol or Dianabol, without liver support.
• Using aromatase inhibitors preemptively, as this can throw off hormonal balance.

PCT after a RAD-140 cycle

Although RAD-140 is not a steroid, it affects the body strongly enough that PCT after a completed cycle is usually necessary - especially if the cycle was long (8+ weeks) or the dose was high (10+ mg).

Why is PCT needed?

RAD-140 suppresses the hypothalamic-pituitary-testicular axis (HPTA), which can lead to:

• a drop in LH and FSH,
• reduced natural testosterone production,
• a possible increase in prolactin and dysregulation of estradiol, the mechanism of which I explained in detail above,
• side effects such as low libido, brain fog, fatigue, and low mood.

A properly run PCT helps to:

• restore natural hormone production faster,
• preserve the muscle gained during the cycle,
• minimize the negative effects of coming off.

Most commonly used medications in PCT

Tamoxifen (Nolvadex):

• Dosage: 40/40/20/20 mg over 4 weeks
• Blocks estrogen receptors in the pituitary, which raises LH and FSH
• An older-generation medication

Clomid (Clomiphene):

• Dosage: 50/50/25/25 mg over 4 weeks
• Works differently from tamoxifen - it stimulates the pituitary by modulating estrogen receptors in the hypothalamus, which increases GnRH secretion and then LH and FSH
• Generally preferred over tamoxifen

Enclomiphene, a modern alternative to Clomid:

• Fewer side effects, works faster, and is usually better tolerated
• Dosage: 12.5-25 mg per day for 3-4 weeks

Natural support, optional

These will not replace proper PCT, but they can support recovery:

• Ashwagandha (KSM-66) - cortisol reduction and mood support
• ZMA (zinc + magnesium + B6) - support for sleep quality and hormonal function
• Tongkat Ali, Fadogia Agrestis - pro-libido and adaptogenic effects
• Boron - supports free testosterone levels by lowering SHBG and may reduce prolactin; an effective dose is 3-10 mg per day. As an example, after using boron myself, 3 mg at night together with zinc, magnesium, and B6, my SHBG was 40.25 nmol/L. After a 2-month course, it dropped to 27.6 nmol/L.

When to start PCT after a RAD-140 cycle?

• RAD-140 has a relatively short half-life, around 16-20 hours.
• PCT is usually started 1-2 days after the last dose. There is no need to wait as you would with injectable steroids.

What blood work should be done before and after the cycle?

Before the cycle:

• Total and free testosterone
• LH, FSH, estradiol, prolactin
• ALT, AST, lipid panel

After the cycle, after 4 weeks of PCT:

• The same markers, plus optionally SHBG and TSH
• Comparing the results will show whether the HPTA has recovered

Skipping PCT - possible consequences

• Prolonged low libido and low energy
• Loss of muscle and strength
• Depression, irritability, brain fog
• Libido and sexual function issues lasting for many weeks or even months

For more information on post-cycle therapy, see the dedicated article: PCT - Post-Cycle Therapy.

RAD-140 vs RAD-150

RAD-150 is a compound chemically very similar to RAD-140 - it is its ester derivative. It is often marketed as an "upgraded version of RAD-140" because the modified molecule is supposed to increase stability and bioavailability.

Differences in chemical structure

• RAD-140: a classic SARM from the group of non-steroidal androgen receptor (AR) agonists
• RAD-150: RAD-140 with an attached ester group, which:
  • theoretically increases its half-life,
  • improves resistance to enzymatic breakdown,
  • may delay peak blood concentration.

Duration of action and bioavailability

• RAD-140: half-life of around 16-20 hours, with peak concentration reached after a few hours,
• RAD-150: longer release profile, with some sources suggesting 36-48 hours,
• theoretically, one dose every 24-36 hours should be enough, although in practice many users still take it daily.

Anabolic vs. androgenic effects

Practical differences - is switching to RAD-150 worth it?

• RAD-140 is much better studied - we know its effects on the hormonal axis, lipid profile, liver, and neuroprotective activity.
• RAD-150 is newer - it looks better on paper, but solid clinical data is lacking.
• In practice, users report similar anabolic effects, with possibly less fluctuation in mood and energy levels, which may be related to the slower release profile.

Comparative dosing

• RAD-140: 10-20 mg per day
• RAD-150: 10-20 mg per day, or every 36 hours if the longer half-life is taken into account

No scientific research on RAD-150

There are currently no scientific publications on RAD-150. All available information comes from user experiences and manufacturers.

Conclusion: RAD-150 may be an interesting alternative, but there is no clinical evidence confirming its superiority over RAD-140. For people who prioritize safety and predictability, standard RAD-140 remains the better choice.

Summary - Is RAD-140 worth using?

RAD-140 (Testolone) is one of the strongest and most promising SARMs available on the market. It combines high anabolic effectiveness with a theoretically lower risk of side effects than classic anabolic steroids.

Who is it for?

• people whose goal is lean muscle mass without excess water retention,
• people training naturally who want to try something stronger than conventional supplements,
• athletes during recomposition or an aggressive cut,
• bodybuilders who want to minimize the number of androgenic compounds they use,
• women - but only with extreme caution and at low doses. Personally, I do not recommend it.

Pros:

• Strong anabolic effects
• Selective action - fewer side effects than steroids
• No aromatization to estrogen
• Neuroprotective effects and a positive impact on bone health
• Well tolerated at doses of 10-15 mg per day

Cons:

• Significant hormonal suppression with longer cycles
• Potential impact on the liver and lipid profile
• No medical approval, still research only status
• Risk of counterfeits and low-quality products

Alternatives:

• Ostarine (MK-2866): a weaker but safer SARM
• LGD-4033: strong, but more suppressive than RAD-140
• Anavar (Oxandrolone): a classic steroid with a similar anabolic profile, but with a risk of hepatotoxicity
• RAD-150: a newer version, but with very little research behind it

RAD-140 is a powerful tool - but like any tool, it requires responsible use. With a sensible approach, proper dosing, and regular blood work, it can produce excellent results in terms of strength, muscle mass, and physique quality.

Disclaimer / Legal Notice

The information contained in this material is for educational purposes only and does not constitute medical advice, diagnosis, or a treatment recommendation. RAD-140 (Testolone) is not an approved drug or dietary supplement and is intended for research purposes only.

Using substances such as SARMs may involve health risks and should always be preceded by consultation with a doctor and appropriate laboratory testing. The author assumes no responsibility for any consequences resulting from irresponsible or illegal use of the compounds described.