RAD-150 (TLB-150)

What Is RAD-150 (TLB-150)?

RAD-150, also known as TLB-150 or TLB-150 Benzoate, is an esterified derivative of RAD-140 (Testolone). It is not a separate SARM in its own right but a chemically modified version of RAD-140 with a benzoate ester group attached to extend the compound’s half-life and improve pharmacokinetic stability.

If you’re looking to buy RAD-150 in the UK, sarms.co.uk supplies research-grade TLB-150 Benzoate capsules with 99%+ HPLC-verified purity, full Certificates of Analysis, and free next-day UK delivery. Every batch is manufactured in GMP-certified UK facilities and independently tested by third-party laboratories. Whether you’re searching for RAD-150 for sale UK, TLB-150 SARM buy UK, or the best place to buy RAD-150 online, our HPLC-tested capsules meet the highest quality standards available.

The logic behind RAD-150 is straightforward: RAD-140 Testolone is one of the most potent and extensively studied non-steroidal SARMs, with a Phase I clinical trial and multiple preclinical studies. However, its estimated half-life of approximately 60 hours, while already long for a SARM, could theoretically be extended further. By attaching a benzoate ester, RAD-150 theoretically extends the active duration and smooths out plasma concentration peaks and troughs. This is the same esterification strategy used for decades in traditional testosterone esters (testosterone enanthate, cypionate, propionate), where the ester controls the release rate of the active hormone.

However, RAD-150 has significantly less published research than its parent compound RAD-140. No human clinical trials have been conducted on RAD-150 specifically, no pharmaceutical company formally developed it, and the available preclinical data is limited. The compound’s pharmacological credibility is essentially borrowed from RAD-140’s evidence base and the well-established prodrug ester concept.

Compound Profile

Chemical Name	2-chloro-4-[[(1R,2S)-1-[5-(4-cyanophenyl)-1,3,4-oxadiazol-2-yl]-2-hydroxypropyl]amino]-3-methylbenzonitrile benzoate
Other Names	TLB-150, TLB-150 Benzoate, RAD-150 Benzoate
CAS Number	1208070-53-4
Parent Compound	RAD-140 (Testolone)
Modification	Benzoate ester
Molecular Weight	597.06 g/mol
Half-Life	Extended vs RAD-140 (estimated 48-72+ hours)
Solubility	PEG-300 / DMSO
Classification	Esterified non-steroidal SARM (prodrug)
Developer	Not formally developed by a pharmaceutical company

How Does RAD-150 Work? Mechanism of Action Explained

RAD-150’s mechanism of action is fundamentally the same as RAD-140, because RAD-150 is RAD-140 once the benzoate ester group is cleaved in the body. The ester modification affects pharmacokinetics (how long the compound stays active and how it is released) but not pharmacodynamics (what it does at the androgen receptor).

Prodrug Ester Hydrolysis

When RAD-150 TLB-150 enters the body, esterase enzymes in the blood and tissues cleave the benzoate ester group, releasing the active RAD-140 molecule. This hydrolysis process occurs gradually, which is the mechanism by which the ester extends the compound’s effective duration. The benzoate ester itself has no pharmacological activity at the androgen receptor. It is purely a delivery mechanism that controls the rate at which active RAD-140 becomes available.

Androgen Receptor Agonism (via RAD-140)

Once liberated from the ester, RAD-140 binds to androgen receptors in skeletal muscle and bone tissue as a potent full agonist. RAD-140’s reported anabolic-to-androgenic selectivity ratio of approximately 90:1 means it produces strong anabolic signalling in target tissues while causing substantially less stimulation in reproductive tissues like the prostate. This tissue selectivity is inherited entirely by RAD-150, since the active molecule is identical.

Extended Duration and Smoother PK Profile

The primary pharmacological advantage of esterification is a smoother plasma concentration curve. Short-acting compounds produce peak-and-trough patterns where plasma levels spike after dosing and decline rapidly before the next dose. Esterified compounds release active molecule more gradually, reducing these fluctuations. In theory, RAD-150 should produce more stable RAD-140 plasma concentrations throughout the dosing interval, potentially reducing the magnitude of peak-related side effects while maintaining more consistent receptor activation.

No Aromatisation

Like its parent compound RAD-140, RAD-150 does not undergo aromatisation (conversion to oestrogen). The ester modification does not change this property. There is no risk of oestrogenic side effects such as gynecomastia or water retention from RAD-150.

Same Tissue Selectivity as RAD-140

RAD-150 inherits RAD-140’s favourable selectivity profile. The benzoate ester does not alter the binding affinity, receptor selectivity, or downstream gene expression patterns of the active RAD-140 molecule. All of the tissue-selective properties demonstrated in RAD-140’s preclinical and clinical studies apply to the active compound released by RAD-150.

RAD-150 vs RAD-140: What Is Actually Different?

The RAD-150 vs RAD-140 comparison is the most important question for researchers evaluating this compound. Since RAD-150 is a prodrug of RAD-140, the differences are entirely pharmacokinetic, not pharmacodynamic. Understanding what changes (and what doesn’t) is essential for making an informed research decision.

Factor	RAD-150 (TLB-150)	RAD-140 (Testolone)
Active compound	RAD-140 (after ester cleavage)	RAD-140 (direct)
Chemical modification	Benzoate ester attached	None (parent compound)
Molecular weight	597.06 g/mol (heavier due to ester)	393.83 g/mol
Estimated half-life	Extended (~48-72+ hours)	~60 hours
Plasma concentration profile	Smoother (theoretical)	Standard peak-and-trough
Human clinical trials	None	Phase I completed (cancer patients)
Published research	Very limited	Multiple preclinical + Phase I human
Developer	No formal pharmaceutical development	Radius Health
Mechanism at AR	Identical once de-esterified	Direct AR agonist
Selectivity ratio	Same as RAD-140 (~90:1)	~90:1 anabolic:androgenic
HPTA suppression	Expected (same active compound)	Dose-dependent suppression
Aromatisation	None	None
PCT required	Yes (same suppression potential)	Yes (dose-dependent)

What Actually Changes

The ester extends the duration of action and potentially smooths the pharmacokinetic profile. That is the only pharmacological difference. The active molecule, receptor binding, tissue selectivity, and downstream effects are identical because the active compound is the same.

What Doesn’t Change

Potency, selectivity, mechanism of action, suppression potential, and side effect profile are all inherited from RAD-140. RAD-150 is not “stronger” or “weaker” than RAD-140 at the receptor level. The ester adds molecular weight without adding pharmacological activity, which means each milligram of RAD-150 contains slightly less active RAD-140 than a milligram of pure RAD-140 (approximately 66% by mass, as the benzoate ester accounts for roughly 34% of the total molecular weight).

The Trade-Off

RAD-150 offers potentially more stable blood levels and less frequent dosing. In exchange, you lose the evidence base. RAD-140 has a Phase I human clinical trial (Miller et al., 2022), extensive preclinical studies, neuroprotection data, and formal pharmaceutical development by Radius Health. RAD-150 has none of these. If evidence quality is your priority, RAD-140 is the better-characterised compound. If the extended PK profile is specifically relevant to your research, RAD-150 may be of interest.

Published Research on RAD-150

Published research specifically on RAD-150 (TLB-150) is extremely limited. The compound’s scientific basis rests on two pillars: the well-established ester prodrug concept and the extensive research on its parent compound RAD-140.

The Ester Prodrug Concept

Esterification of active pharmaceutical compounds to control their release rate is one of the oldest and most validated strategies in pharmacology. Testosterone benzoate itself has been used clinically since the 1930s. The principle is well-proven: attaching an ester group to a hydroxyl group creates a prodrug that is gradually hydrolysed by esterase enzymes, releasing the active compound over an extended period. This approach has been applied to hundreds of drugs across multiple therapeutic areas.

RAD-140 Research Base (Parent Compound)

Since RAD-150 converts to RAD-140 in vivo, the parent compound’s research base is directly relevant:

• Phase I Clinical Trial: Miller et al. (2022) conducted a first-in-human dose-escalation study of RAD-140 in postmenopausal women with hormone receptor-positive breast cancer. The study established initial safety parameters and pharmacokinetic profiles in humans. PMID: 36368886
• Neuroprotection: Jayaraman et al. (2014) demonstrated RAD-140 was neuroprotective in cultured neurons and kainate-lesioned rats, suggesting potential applications beyond musculoskeletal research. PMID: 24428527
• Preclinical Characterisation: Multiple preclinical studies have characterised RAD-140’s tissue selectivity, demonstrating a ~90:1 anabolic-to-androgenic ratio and dose-dependent increases in lean mass in animal models
• Breast Cancer Research: RAD-140 has been investigated as a potential treatment for androgen receptor-positive breast cancer, adding a clinical research dimension beyond sports science

What’s Missing for RAD-150 Specifically

• No human clinical trials: Zero human data on RAD-150 itself
• No formal PK characterisation: The actual half-life extension has not been measured in controlled studies. The “48-72+ hours” estimate is theoretical, based on the known behaviour of benzoate esters
• No head-to-head comparison: No study has directly compared RAD-150 to RAD-140 in terms of pharmacokinetics, efficacy, or safety
• No pharmaceutical development: Unlike RAD-140, which was developed by Radius Health (a publicly traded biotech company), RAD-150 was not formally developed, patented, or advanced through a drug development pipeline by any pharmaceutical company
• No published selectivity data: While RAD-150 should theoretically inherit RAD-140’s selectivity, this has not been independently confirmed for the esterified compound

⚠️ Important: RAD-150 has NO human clinical data. Its pharmacological credibility is entirely borrowed from RAD-140’s evidence base and the well-established prodrug ester concept. It is sold for research purposes only.

RAD-150 Dosage and Administration (Research Use Only)

No human studies establish dosing for RAD-150. All RAD-150 dosage references are extrapolated from RAD-140 data, adjusted for the molecular weight difference introduced by the benzoate ester.

• Clinical trial dosages: None. No human trials have been conducted on RAD-150.
• Commonly referenced RAD-150 dosage: 10-20 mg per day is the most frequently cited research range
• Molecular weight adjustment: The benzoate ester adds approximately 34% to the molecular weight. Each milligram of RAD-150 delivers approximately 0.66 mg of active RAD-140 equivalent. Commonly referenced dosages already account for this
• RAD-150 half-life: Estimated 48-72+ hours (extended vs RAD-140’s ~60 hours). This estimate is theoretical and has not been measured in humans
• RAD-150 cycle length: 8-12 weeks is commonly referenced for research protocols
• Administration: Oral capsule (10 mg per capsule)

A note on dosing comparisons: Because RAD-150 must be de-esterified to release active RAD-140, direct milligram-to-milligram comparisons with RAD-140 are misleading. 10 mg of RAD-150 delivers approximately 6.6 mg of active RAD-140. Researchers comparing RAD-150 dosage to RAD-140 dosage should account for this difference when designing protocols.

RAD-150 Side Effects: What We Know and What We Don’t

The RAD-150 side effect profile in humans has not been studied. Since the active compound is RAD-140, the side effect profile should theoretically mirror RAD-140’s, with one potential modification: the smoother PK profile may reduce peak-related effects while the extended duration means any suppressive effects persist longer after the last dose.

HPTA Suppression

RAD-150 is expected to cause dose-dependent HPTA suppression because the active compound (RAD-140) is a potent AR agonist. The Phase I RAD-140 trial showed dose-dependent decreases in testosterone, LH, and FSH at higher doses. RAD-150 should produce comparable suppression at equivalent active doses. The extended half-life may mean suppression persists longer after cessation compared to unesterified RAD-140.

Liver Considerations

RAD-140’s Phase I trial reported some liver enzyme elevations at higher doses in cancer patients (who were also receiving other treatments). RAD-150 is expected to have a similar hepatic profile. The ester itself is hydrolysed to benzoic acid, which is a normal metabolite that the body conjugates with glycine and excretes as hippuric acid. The ester component adds no hepatotoxicity risk.

Lipid Changes

Like other SARMs, RAD-150 may cause mild HDL suppression through its RAD-140 activity. This is a class effect observed with all AR agonists, including in the RAD-140 Phase I trial and Ostarine/LGD-4033 clinical trials.

Other Theoretical Considerations

• No aromatisation means no oestrogenic side effects (gynecomastia, water retention)
• No DHT conversion means no DHT-related side effects beyond direct AR activation
• Extended duration means longer washout period before hormonal recovery begins
• Long-term RAD-150 side effects are completely unknown

Does RAD-150 Require PCT?

Yes. Since RAD-150 releases RAD-140 (a potent AR agonist), it carries the same potential for dose-dependent HPTA suppression. The RAD-140 Phase I trial documented dose-dependent decreases in testosterone, LH, and FSH, confirming that this class of compound causes suppression at effective doses.

The extended half-life of RAD-150 adds a timing consideration for PCT: the active compound takes longer to clear the system after the last dose, which means the window between last dose and PCT initiation may need to be longer than with standard RAD-140. Most researchers account for approximately 2-3 half-lives of clearance before beginning PCT protocols.

RAD-150 Stacking: Common Research Combinations

RAD-150’s role in stacking protocols is essentially the same as RAD-140’s, since the active compound is identical. The extended PK profile may offer some advantages in stack protocols where stable plasma concentrations are desirable.

RAD-150 and MK-677 Stack

The RAD-150 MK-677 stack combines AR-mediated anabolism (via RAD-140 release) with GH/IGF-1 axis elevation from MK-677 Ibutamoren. MK-677 does not cause HPTA suppression, making it a complementary addition that targets an independent growth pathway. This is one of the most commonly referenced RAD-150 stacking combinations for recovery and mass-focused research.

RAD-150 and Cardarine Stack

Pairing RAD-150 with Cardarine GW-501516 combines AR-mediated anabolism with PPARδ-mediated fat oxidation and endurance enhancement. Cardarine does not interact with androgen receptors and does not cause HPTA suppression, making this a common recomposition pairing where the RAD-150 Cardarine stack targets simultaneous muscle preservation and fat loss.

RAD-150 and Ostarine Stack

The RAD-150 Ostarine stack combines a potent AR agonist (via RAD-140) with the most clinically studied SARM, MK-2866 Ostarine. Both compounds target androgen receptors, so the combined HPTA suppression will be greater than either alone. Some researchers use this combination to target different tissue responses, as Ostarine and RAD-140 have different receptor binding kinetics.

RAD-150 and LGD-4033 Stack

Combining RAD-150 with LGD-4033 Ligandrol pairs two potent AR agonists for maximum anabolic signalling. This is an aggressive combination: both compounds cause dose-dependent HPTA suppression, and the combined impact on the hormonal axis will be substantial. This stack is referenced in advanced research protocols targeting maximum lean mass effects.

RAD-150 and YK-11 Stack

The RAD-150 YK-11 stack combines AR agonism (via RAD-140 release) with YK-11 Myostine’s theoretical myostatin-inhibiting properties. The rationale is targeting two independent muscle growth pathways: androgen receptor activation and myostatin suppression via follistatin induction. Both compounds are expected to cause HPTA suppression.

Is RAD-150 Better Than RAD-140?

“Better” depends entirely on what your research requires. RAD-150 is not pharmacologically superior to RAD-140 at the receptor level. The active compound is identical. The only advantage RAD-150 offers is a potentially extended and smoother pharmacokinetic profile.

Choose RAD-150 When

• Your research specifically requires extended-duration AR agonist exposure
• Stable plasma concentrations are important for your protocol design
• Less frequent dosing is operationally preferable
• You are studying esterified prodrug pharmacokinetics

Choose RAD-140 When

• Evidence quality and clinical validation are priorities
• You want a compound with published human safety data
• Dose flexibility (shorter acting = faster washout) is important
• You prefer a compound with formal pharmaceutical development history
• Peer-reviewed citations are needed for your research documentation

The honest take: most researchers favour RAD-140 because the evidence base is substantially stronger. RAD-150 is a valid research tool for protocols where the extended PK profile is specifically relevant, but choosing it means accepting a significantly weaker evidence foundation. The ester prodrug concept is sound; the specific application to RAD-140 as RAD-150 simply hasn’t been validated independently.

Who Is Researching RAD-150?

• Extended-release SARM researchers investigating longer-acting AR agonists for protocols where stable plasma concentrations are critical
• Pharmacokinetic comparison researchers studying esterified vs non-esterified SARM profiles to understand how ester modifications affect absorption, distribution, and elimination
• Muscle wasting researchers leveraging RAD-140’s established mechanism with a modified delivery system for protocols requiring sustained receptor activation
• Prodrug development researchers studying ester modifications of existing SARMs as a model for prodrug design in this compound class
• Stack researchers using RAD-150 as a longer-acting alternative to RAD-140 in multi-compound protocols

Why Buy RAD-150 from sarms.co.uk?

Purity You Can Verify

Every batch of RAD-150 (TLB-150) is independently tested via High-Performance Liquid Chromatography (HPLC) by accredited third-party laboratories. We publish full Certificates of Analysis for every batch. Download the PDF directly from this page and verify with the testing lab independently. With a compound that has no formal pharmaceutical oversight, third-party purity verification is especially critical.

Proper Concentration

10 mg per capsule, 90 capsules per bottle. No underdosed products, no proprietary blends, no ambiguity. Precise dosing is essential for any research protocol, particularly with a prodrug compound where the active-to-total mass ratio matters.

UK Manufactured

Compounded in GMP-certified UK facilities. Not imported from unregulated overseas laboratories. Raw materials are tested before compounding. Finished products are tested after compounding. Two-stage quality control with full documentation at every step.

Capsules for Consistent Dosing

We sell RAD-150 in capsule form for consistent per-dose accuracy. Capsules eliminate the measurement variability associated with liquid or powder forms, ensuring each dose delivers exactly 10 mg of RAD-150 (TLB-150 Benzoate).

Free Next-Day UK Delivery

All orders ship free with next-day UK delivery. No minimum order, no hidden shipping fees.

Storage and Handling

• Store at room temperature (15-25°C) in a cool, dry place
• Keep away from direct sunlight and moisture
• Keep the container tightly sealed after each use
• Keep out of reach of children
• Do not use past the expiry date printed on the label
• Shelf life: 24 months when stored correctly

Frequently Asked Questions About RAD-150

What is RAD-150?

RAD-150 (TLB-150) is an esterified version of RAD-140 (Testolone). A benzoate ester group is attached to the RAD-140 molecule to extend its half-life and provide a smoother pharmacokinetic profile. Once the ester is cleaved by enzymes in the body, it releases active RAD-140.

Is RAD-150 stronger than RAD-140?

No. The active compound is the same (RAD-140), so the pharmacological potency at the androgen receptor is identical. RAD-150 may provide more stable blood levels due to slower release, but the peak effect is comparable. Each milligram of RAD-150 actually delivers less active RAD-140 than a milligram of pure RAD-140, because the ester adds molecular weight without pharmacological activity.

What is the RAD-150 half-life?

The RAD-150 half-life is estimated at 48-72+ hours, extended compared to RAD-140’s approximately 60 hours. This estimate is theoretical, based on the known behaviour of benzoate esters. The actual half-life has not been measured in human pharmacokinetic studies.

What are the RAD-150 side effects?

RAD-150 side effects have not been studied in humans. Since the active compound is RAD-140, the side effect profile is expected to mirror RAD-140’s, including dose-dependent HPTA suppression, possible mild HDL suppression, and potential liver enzyme elevations at higher doses. The extended duration may mean suppressive effects persist longer after cessation.

Does RAD-150 require PCT?

Yes. RAD-150 releases RAD-140, a potent AR agonist confirmed to cause dose-dependent HPTA suppression in the Phase I clinical trial. PCT protocols should be considered, particularly at higher doses or longer cycles. The extended half-life means the active compound takes longer to clear, which may affect PCT timing.

Should I use RAD-150 or RAD-140?

RAD-140 has substantially more published evidence, including a Phase I human clinical trial, neuroprotection studies, and formal pharmaceutical development. RAD-150 offers a potentially longer half-life and smoother PK profile but with significantly less supporting data. Most researchers favour the better-characterised parent compound unless the extended PK is specifically relevant to their protocol.

How does the ester affect RAD-150 dosing?

The benzoate ester adds approximately 34% to the molecular weight. Each milligram of RAD-150 contains roughly 0.66 mg of active RAD-140 equivalent. Commonly referenced dosages (10-20 mg/day) already account for this molecular weight difference. Direct milligram-to-milligram comparisons with RAD-140 dosages are misleading without this adjustment.

Is RAD-150 legal in the UK?

RAD-150 is legal to purchase in the UK for research purposes. It is not approved for human consumption by the MHRA. It is on WADA’s prohibited list and cannot be used in competitive sport.

Can you stack RAD-150 with MK-677?

The RAD-150 MK-677 stack is one of the most frequently referenced combinations, pairing AR-mediated anabolism with GH/IGF-1 axis elevation. MK-677 does not cause HPTA suppression, making it a complementary addition. This combination targets two independent growth pathways simultaneously.

What is the difference between RAD-150 and TLB-150?

RAD-150 and TLB-150 are the same compound. TLB-150 (sometimes written as TLB-150 Benzoate) is an alternative designation for the esterified RAD-140 derivative. Both names refer to the same chemical entity with the same CAS number (1208070-53-4).

Is RAD-150 better than RAD-140 for bulking?

The active compound is the same, so the anabolic potential is identical at equivalent active doses. RAD-150 may offer more stable blood levels, but it does not provide greater anabolic stimulation. RAD-140 has the advantage of a stronger evidence base and a Phase I human clinical trial demonstrating safety parameters.

How long does RAD-150 stay in your system?

Based on the estimated 48-72+ hour half-life, RAD-150 (and its active metabolite RAD-140) would take approximately 10-15 days to substantially clear the system (5 half-lives). This is relevant for PCT timing and for researchers subject to anti-doping testing, as detection windows may be longer than for unesterified RAD-140.

Related SARMs and Research Compounds

• RAD-140 Testolone – the parent compound of RAD-150 with Phase I human clinical trial data, extensive preclinical research, and formal pharmaceutical development by Radius Health. The better-characterised alternative
• LGD-4033 Ligandrol – the only SARM with Phase I human data showing measurable lean mass gains. An alternative potent AR agonist with an independent evidence base
• MK-2866 Ostarine (Enobosarm) – the most clinically studied SARM with Phase II and III trial data. A moderate-potency alternative with the strongest evidence base of any SARM
• MK-677 Ibutamoren – a growth hormone secretagogue commonly stacked with RAD-150 for complementary GH/IGF-1 axis support without additional HPTA suppression
• Cardarine GW-501516 (Endurobol) – a PPARδ agonist frequently paired with RAD-150 in recomposition protocols targeting simultaneous muscle preservation and fat loss
• YK-11 Myostine – a steroidal SARM with myostatin-inhibiting properties, sometimes combined with RAD-150 in advanced research protocols
• SR-9009 Stenabolic – a Rev-Erbα agonist studied for metabolic and circadian rhythm modulation
• Andarine S4 – a moderate-potency non-steroidal SARM with extensive preclinical data on muscle, bone, and fat tissue effects

References and Further Reading

• Miller CP, et al. (2022). “Design, Synthesis, and Preclinical Characterization of the Selective Androgen Receptor Modulator (SARM) RAD140.” ACS Medicinal Chemistry Letters. PMID: 36368886 (parent compound RAD-140)
• Jayaraman A, et al. (2014). “Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats.” Endocrinology, 155(4), 1398-1406. PMID: 24428527 (parent compound RAD-140)
• Narayanan R, et al. (2018). “Selective Androgen Receptor Modulators (SARMs) as Function Promoting Therapies.” Current Opinion in Clinical Nutrition and Metabolic Care, 21(3), 233-237. PMID: 29528862

Disclaimers

• RAD-150 (TLB-150) is sold strictly for laboratory and research purposes only
• This product is not intended for human consumption
• RAD-150 is not a medicine, supplement, or food product
• No human clinical trials or safety data exist for this specific compound
• RAD-150 was not formally developed by a pharmaceutical company
• All pharmacological data is extrapolated from the parent compound RAD-140
• Not suitable for individuals under 18 years of age
• Pregnant or breastfeeding women must not handle this compound
• Researchers should consult qualified professionals and adhere to all applicable regulations
• sarms.co.uk does not provide medical advice and makes no claims regarding therapeutic outcomes
• We are not responsible for any adverse effects resulting from misuse of this product
• The content on this page does not constitute medical advice

Content last reviewed: 25 February 2026