By the SARMs Store editorial team, reviewed by the SARMs Store research team. Products on this site are supplied strictly for laboratory research and are not for human consumption. This guide summarises published studies; it is not medical advice and contains no instructions for use. 18+ only.
How we judged "best"
Most "best SARMs" lists rank compounds by what people say they feel. We cannot do that, because none of these compounds is licensed for human use and anecdote is not evidence. Instead, this guide ranks the compounds in our SARMs UK range by four things a researcher can actually check:
- Depth of the clinical record. How far did the compound get in human trials, and how many published studies exist?
- Clarity of the mechanism. Is it well characterised, and is it actually a SARM?
- Known problems. Was development stopped, and why?
- Quality you can verify. Can you get it as a fixed-strength capsule with a batch certificate?
The ranking at a glance
| Rank | Compound | Clinical stage reached | Best documented in | Main caution in the literature |
|---|---|---|---|---|
| 1 | Ostarine (MK-2866) | Phase III | Muscle wasting, cancer cachexia | Suppression of natural testosterone in trials |
| 2 | Ligandrol (LGD-4033) | Phase II | Healthy volunteers, hip fracture recovery | Dose-dependent hormone suppression; case reports of liver injury |
| 3 | MK-677 (ibutamoren) | Phase II | Growth hormone and IGF-1 levels | Not a SARM; raised blood glucose in some trials |
| 4 | RAD-140 (testolone) | Phase I | Breast cancer | Case reports of liver injury |
| 5 | Cardarine (GW-501516) | Phase II, then stopped | Lipids and metabolism | Development halted in 2007 after rodent cancer findings |
| 6 | Andarine (S-4) | Preclinical | Rodent muscle and bone | Visual effects reported in animal studies |
| 7 | YK-11 | Cell and rodent studies | Myostatin and follistatin in vitro | Steroidal structure; rat studies report hippocampal oxidative stress |
| 8 | SR-9009 (stenabolic) | Rodent studies | Circadian rhythm and metabolism | Very poor oral bioavailability |
| 9 | S-23 | Rodent studies | Male contraception models | Strong hormone suppression in rats |
| 10 | ACP-105 | Rodent studies | Androgen receptor binding | Very little published data |
1. Ostarine (MK-2866): the most studied SARM
Ostarine, also called enobosarm, has the longest clinical record of any SARM. GTx Inc. took it through phase II trials in healthy older adults (Dalton and colleagues, 2011) and into phase III trials in cancer cachexia, the muscle loss that accompanies advanced cancer. It did not gain a licence, but no other SARM has as much human data behind it, which is why it is the usual starting point for anyone new to the category. See the Ostarine guide and Dexterz Labs Ostarine MK-2866 10mg.
2. Ligandrol (LGD-4033): strong data from a small set of trials
LGD-4033 was developed by Ligand Pharmaceuticals and later licensed to Viking Therapeutics as VK5211. A 2013 phase I trial in healthy young men (Basaria and colleagues, Journals of Gerontology) measured lean mass and hormone changes over 21 days, and a phase II trial followed in older adults recovering from hip fracture. The trials also documented dose-dependent suppression of testosterone and SHBG. See the LGD-4033 guide and Dexterz Labs Ligandrol LGD-4033 10mg.
3. MK-677 (ibutamoren): not a SARM, but a deep record
MK-677 and ibutamoren are the same compound; Nutrobal is an older trade name. It is a growth hormone secretagogue that mimics ghrelin, so it is not a SARM, but it is studied alongside them and has more human trial data than most SARMs, including a two-year trial in older adults (Nass and colleagues, Annals of Internal Medicine, 2008). The same trials reported increased appetite and raised fasting glucose. See the MK-677 guide and Dexterz Labs MK-677 10mg.
4. RAD-140 (testolone): early clinical data
RAD-140 was developed by Radius Health and reached a first-in-human phase I trial in postmenopausal women with advanced oestrogen receptor positive breast cancer (ClinicalTrials.gov NCT03088527). Most of what is known about its effects on muscle comes from primate and rodent work. Several case reports describe liver injury in people using unregulated products. See the RAD-140 guide and Dexterz Labs RAD-140 5mg.
5. Cardarine (GW-501516): well studied, then stopped
Cardarine is a PPAR-delta agonist, not a SARM. GlaxoSmithKline studied it for lipid and metabolic disorders and reported favourable lipid changes in early human trials, but halted development in 2007 after long-term rodent studies found cancers in multiple organs. It remains one of the most researched compounds in metabolic and endurance studies. See the Cardarine guide and Dexterz Labs Cardarine 10mg.
6 to 10. The preclinical compounds
Andarine (S-4) is one of the earliest non-steroidal SARMs and has a solid rodent literature on muscle and bone, plus reports of visual changes in animal studies. YK-11 is a steroidal SARM studied mainly in cell culture, where it raised follistatin, a protein that blocks myostatin, with a few rodent studies since 2021. SR-9009 (stenabolic) targets the body clock protein Rev-ErbA and is known mainly from mouse studies; its oral bioavailability is very low. S-23 was studied as a male contraceptive in rats and suppresses hormones strongly. ACP-105 has very little published data beyond receptor binding studies. Each has its own guide, linked from the SARMs collection.
Best SARMs by research area
| Research area | Compounds with the most relevant published work |
|---|---|
| Lean mass and muscle wasting | Ostarine, LGD-4033, RAD-140 |
| Bone density | Ostarine, Andarine |
| Growth hormone and IGF-1 | MK-677 |
| Lipids and metabolism | Cardarine, SR-9009 |
| Myostatin pathways | YK-11 |
Researchers often study these in combination; our SARMs stacks guide sets out the combinations that appear in the literature, and the stacks in our range group them at a lower price than buying each compound separately. The compounds ordered most often are grouped in our best sellers collection, and first-time researchers can start with the beginner SARMs range.
What "best" cannot tell you
No ranking can tell you how a compound will behave in a person, because none of these compounds has completed the trials needed for a licence. What a ranking can do is show you which compounds have been studied most carefully, and which carry known problems. The other half of "best" is quality: a well-studied compound in a mislabelled bottle is worthless for research.
How to check quality before you buy
- Ask for a batch-specific certificate of analysis with HPLC purity and the batch number that is on the bottle. Our How to read a certificate of analysis guide explains each line.
- Compare milligrams per capsule, not price per bottle.
- Prefer capsules over liquids for stability.
- Buy from a UK supplier to avoid customs seizures, and avoid any supplier that gives doses.
Are SARMs legal in the UK?
SARMs are not controlled drugs in the UK, so buying and possessing them for research is lawful. They are not licensed medicines and cannot be sold for human consumption. All SARMs are banned in sport under WADA section S1.2. Full detail is in our guide Are SARMs legal in the UK?
Frequently asked questions
What is the best SARM for a first research project?
Ostarine, because it has the largest published human data set, so results can be compared with the literature.
Is MK-677 a SARM?
No. It is a growth hormone secretagogue. It is grouped with SARMs because the two are often studied together.
Which SARM has the most clinical trials?
Ostarine (enobosarm), which reached phase III.
Are the best SARMs available on prescription in the UK?
No. No SARM is licensed in the UK or elsewhere.
Sources
- Dalton JT, Barnette KG, Bohl CE, et al. The selective androgen receptor modulator GTx-024 (enobosarm) improves lean body mass and physical function in healthy elderly men and postmenopausal women. Journal of Cachexia, Sarcopenia and Muscle. 2011;2(3):153-161. PubMed 22031847
- Basaria S, Collins L, Dillon EL, et al. The safety, pharmacokinetics, and effects of LGD-4033, a novel nonsteroidal oral selective androgen receptor modulator, in healthy young men. Journals of Gerontology A. 2013;68(1):87-95. PubMed 22459616
- Nass R, Pezzoli SS, Oliveri MC, et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults. Annals of Internal Medicine. 2008;149(9):601-611. PubMed 18981485
- Radius Health. Phase 1, first-in-human study of RAD140 in postmenopausal women with breast cancer. ClinicalTrials.gov NCT03088527.
- World Anti-Doping Agency. Prohibited List 2026, section S1.2.
This guide summarises published studies and is for laboratory reference only. Products are not for human consumption.