LGD-4033, sold as ligandrol, is a non-steroidal selective androgen receptor modulator (SARM) developed as a candidate treatment for muscle wasting and related conditions. Among the popular muscle SARMs it occupies a useful middle spot: more potent than ostarine, but with a single well-known human study that actually put numbers on both its benefit and its suppression. It never reached approval as a medicine, and what is sold today is unregulated research-chemical material. This guide sets out what that one good study measured and where the evidence stops.
How it works
Ligandrol binds the androgen receptor and activates it, with the class's intended pattern of stronger action in muscle and bone than in tissues like the prostate. It is a high-affinity binder, which is why it is more potent per milligram than ostarine. As with the whole class, that same receptor activation is what drives its effect on your own hormone production, so potency and suppression travel together.
What the human data shows
Ligandrol has one frequently cited phase 1 trial in healthy young men. Over a 21-day dosing period at modest doses, it produced a dose-dependent increase in lean body mass alongside clear, dose-dependent falls in total testosterone, free testosterone, sex-hormone-binding globulin, and follicle-stimulating hormone. Levels trended back toward baseline after the drug was stopped. That is genuinely valuable: it is direct human evidence that ligandrol both adds lean mass and shuts down the gonadal axis, measured in the same study.
The important qualifiers:
- It was a single, short study — three weeks — in healthy young men, not a long-term or real-world design.
- The lean-mass change over that window was real but modest, on the order of about a kilogram, not a dramatic transformation.
- The doses studied were lower than what people typically take recreationally, so the trial understates both the effect and the suppression you would expect at higher, longer use.
Realistic effects
What to expect, honestly, is a modest anabolic effect — some added lean mass and strength over a cycle — larger than ostarine per milligram, smaller and less aggressive than what RAD-140 users describe. User reports also mention water retention and lethargy in some cases. The single controlled study supports the lean-mass direction; the finer-grained user claims are anecdote, and they are only meaningful if the product is actually ligandrol, which grey-market supply does not guarantee.
Suppression and PCT considerations
Unlike most of the class, ligandrol's suppression is not a matter of inference — it was measured directly in that phase 1 study, and it was dose-dependent. Because the body reads ligandrol as an androgen, the brain reduces the LH and FSH signals that drive testosterone production, and your own output falls.
What that means in practice:
- Assume some degree of suppression from any real ligandrol use, more at higher doses and longer durations.
- In the trial, hormones drifted back toward baseline after stopping, which is reassuring for short, low-dose exposure but says nothing about recovery after the heavier or stacked use common recreationally.
- The standard recovery tools are SERMs such as tamoxifen or clomifene, which prompt the brain to release more LH and FSH and restart natural production. Whether an individual needs one, and at what dose, is not established by trials in SARM users — that data does not exist. Bloodwork before, during, and after is the only reliable way to know your own response. SERMs are prescription drugs with their own side effects.
Safety signals
The controlled data is short, so the long-term safety picture is simply unknown. Within what has been observed, reductions in HDL cholesterol are commonly reported across the muscle SARMs, and the same lipid concern applies here. Ligandrol does not carry the prominent cluster of liver-injury case reports that RAD-140 does, but that reflects less data and less notoriety, not a demonstrated clean bill of health. Hard cardiovascular endpoints have never been studied for it.
The grey-market problem
Because ligandrol is sold as a research chemical, not a medicine, product quality is unregulated. Independent analyses of products marketed as SARMs have repeatedly found the wrong compound, no active ingredient, unlisted additional drugs, or a substituted anabolic steroid, with doses far from what the label claims. Notably, ligandrol has been implicated in a number of athlete anti-doping cases attributed to contaminated supplements — a concrete example of the label not matching the contents. SARMs are banned by WADA in and out of competition.
Bottom line
Ligandrol is the muscle SARM with the cleanest short human study: three weeks in healthy men showed a modest, dose-dependent lean-mass gain and clear, dose-dependent suppression of the gonadal axis. That makes its core claims — it works a bit, and it shuts you down — better evidenced than for RAD-140. But it is one short study at sub-recreational doses, long-term safety is unknown, lipid effects are a real concern, and the grey-market product may not be ligandrol at all. Expect a moderate effect, expect suppression, and verify with bloodwork. This is reference information, not medical advice.