SARM Showdown: Ostarine vs LGD-4033
We've compared both of these compounds with RAD-140 before, but never with each other. That's a notable gap, because Ostarine (MK-2866) and LGD-4033 (Ligandrol) are probably the two most talked-about SARMs, and they are also the two with the most human research data.
Both are non-steroidal selective androgen receptor modulators. Both have been through human trials. Both come up regularly in lean-mass research. They differ mainly in potency, how far development went, and the kinds of research questions each is usually linked to.
All information is for educational and research purposes only.
Ostarine (MK-2866) — The Most Clinically Studied SARM
Ostarine, also called enobosarm or GTx-024, was developed by GTx Inc. It binds to the androgen receptor with high selectivity for muscle and bone. It was designed to have much less effect on tissues such as the prostate and skin.
Few SARMs have been through as much clinical research. Key milestones include:
- Phase II (Dalton et al., 2011): a 12-week, double-blind, placebo-controlled trial in healthy elderly men and postmenopausal women. It reported gains in lean body mass and improved stair-climb performance compared with placebo.
- Phase III (POWER trials, 2013): studied in patients with non-small-cell lung cancer to prevent muscle wasting. The trials did not meet all of their co-primary endpoints.
- Recent research (Veru Inc.): investigated in androgen receptor–positive breast cancer and, more recently, with GLP-1 weight-loss drugs to see whether it reduces lean-tissue loss during rapid weight loss.
Research profile: milder, well characterised and linked mainly to keeping and moderately gaining lean tissue.
LGD-4033 (Ligandrol) — The Potent Builder
LGD-4033 was developed by Ligand Pharmaceuticals and later licensed to Viking Therapeutics, where it became VK5211. It is also a non-steroidal SARM, but it binds the androgen receptor with very high affinity, even at very small doses.
The key studies are:
- Phase I (Basaria et al., 2013): a 21-day, placebo-controlled study in healthy young men. Even at very low doses, it produced a dose-dependent increase in lean body mass over just three weeks.
- Phase II (Viking Therapeutics, 2017): a trial in older patients recovering from hip fracture, which met its primary endpoint of increased lean body mass.
Research profile: more potent per milligram than Ostarine and linked mainly to building lean tissue and strength.
Research Considerations for Both
Because both compounds act on the androgen receptor, they share some important findings:
- Hormone suppression: Basaria et al. found that LGD-4033 lowered total testosterone, SHBG and HDL cholesterol in a dose-dependent way, even within 21 days. Ostarine studies have reported similar hormone and lipid changes. Tissue selectivity is relative, not absolute.
- Liver findings: there are published case reports of drug-induced liver injury linked to products sold as both compounds. Many of these involved products of unknown purity, which is one reason independent testing matters.
- Regulatory status: neither compound is approved as a medicine anywhere. Both are on the WADA Prohibited List under S1.2 (Other Anabolic Agents).
Side-by-Side Comparison
| Ostarine (MK-2866) | LGD-4033 (Ligandrol) | |
|---|---|---|
| Class | Non-steroidal SARM | Non-steroidal SARM |
| Developer | GTx Inc. (now Veru) | Ligand Pharmaceuticals / Viking Therapeutics |
| Furthest clinical stage | Phase III | Phase II |
| Relative potency | Moderate | High |
| Typical research focus | Keeping lean tissue, recomposition | Lean mass and strength gains |
| Hormone suppression reported | Yes | Yes, even at low doses |
| Half-life (reported) | Around 24 hours | Around 24–36 hours |
Most human data: Ostarine. Its clinical record is the longest and most varied of any SARM.
Most potent: LGD-4033. It had measurable effects on lean mass at doses far below Ostarine's in human studies.
Best documented safety profile: Ostarine, although "documented" is not the same as "safe", and both show the hormone suppression you would expect from androgen receptor agonists.
Which Compound Fits Which Research Goal
- Keeping lean tissue during a calorie deficit or recomposition: Ostarine. This matches its clinical history in muscle-wasting and weight-loss settings.
- Increasing lean mass and strength: LGD-4033. It is more potent, and its Phase I and II data focus on building lean tissue.
- Comparing SARM potency: the two work well as a pair. Their human data allows a rare like-for-like comparison of two SARMs on similar outcome measures.
The two are also often studied together. Our Minotaur Stacked formulation contains both, and its independent lab report shows the measured content of each compound per tablet.
The Verdict
Ostarine and LGD-4033 are not so much rivals as two steps on the same ladder. Ostarine is the milder, better-documented option associated with keeping lean tissue. LGD-4033 is the more potent option associated with building it. Neither is universally better. The right choice depends on the research question.
You can see independent lab analysis for both compounds on our Independent Analysis page.
Further reading
- Dalton JT et al. (2011). The selective androgen receptor modulator GTx-024 (enobosarm) improves lean body mass and physical function in healthy elderly men and postmenopausal women. J Cachexia Sarcopenia Muscle.
- Basaria S et al. (2013). The safety, pharmacokinetics, and effects of LGD-4033, a novel nonsteroidal oral, selective androgen receptor modulator, in healthy young men. J Gerontol A Biol Sci Med Sci.
All products sold by Peak Body are strictly for research purposes only and are not intended for human consumption.
