LGD-4033 (Ligandrol)
Extensively StudiedNonsteroidal SARM developed by Ligand Pharma (later licensed to Viking as VK5211) for muscle wasting; reliably builds lean mass at 5-10… | SARM · Oral
Aliases (4)
▸ Cycle structure & PCT AAS oral
Ramp dose over week 1, hold steady through cycle weeks. Track baseline labs (TT/FT/E2/SHBG/HCT/lipids/LFTs) at week 0; recheck at week 4 and end-of-cycle.
On the last dose, the ester clears over its half-life window . PCT begins after the active compound has cleared.
Standard PCT is enclomiphene 12.5-25 mg/day or clomid 50/50/25/25 over 4 weeks (or nolvadex 20/20/10/10). HCG bridge optional during cycle to preserve testicular volume + faster restart. Bloodwork at PCT week 4 + 8 to confirm HPG axis recovery (LH, FSH, TT back to baseline).
▸ Overview TL;DR
Nonsteroidal SARM developed by Ligand Pharma (later licensed to Viking as VK5211) for muscle wasting; reliably builds lean mass at 5-10 mg/day but predictably suppresses LH/FSH/testosterone, has documented hepatotoxicity case reports in LiverTox, and is FDA-prohibited with research-chem-only sourcing. Hard SKIP for a 20yo with active endocrine and brain development whose stated #1 priority is brain.
▸ Mechanism of action
Selective androgen receptor (AR) modulator: binds AR with high affinity (Ki ~1 nM) but exerts tissue-selective transcriptional effects — strong anabolic signaling in muscle and bone, intentionally weaker effects on prostate, skin, and scalp than testosterone. Selectivity is relative, not absolute: the brain's hypothalamus reads AR activation and downregulates GnRH, which collapses LH and FSH from the pituitary, which suppresses testicular testosterone production. So while SARMs reduce some androgenic side effects vs testosterone, they do not bypass HPG-axis suppression — that is intrinsic to AR agonism in the hypothalamus.
Hepatotoxicity mechanism is not fully characterized; case reports describe a cholestatic/mixed pattern, possibly idiosyncratic, possibly product-contamination-driven (research-chem products often misdosed or contaminated).
▸ Pharmacokinetics No data
▸Quality indicators4 checks
▸ What to expect From notes
- 1OnsetBody-comp changes appear by week 2-3 (water + early lean mass).
- 2PeakWeeks 4-8 — reported strength bump, easier recomposition, slight aggression/drive uptick.
▸ Side effects + safety
- Common (>10% users in forum/case-series reports):
- HPG-axis suppression (dose-dependent, near-universal at 5+ mg/day)
- Libido changes (initial increase, terminal cycle decrease)
- Mild lethargy mid-to-late cycle
- Lipid shifts (LDL up, HDL down — typical of oral AR agonists)
- Less common (1-10%):
- Mood changes — irritability, depressive symptoms cycle-end
- Hair shedding (despite "selectivity" claims)
- Mild hypertension
- Headaches, nausea
- Rare-serious (<1% but worth knowing):
- Drug-induced liver injury (DILI) — cholestatic hepatitis, sometimes severe. Multiple case reports in young healthy men, several requiring hospitalization. LiverTox classifies LGD-4033 as a recognized cause of hepatotoxicity.
- Persistent hypogonadism — case reports of users requiring TRT after repeat SARM cycles.
- Acute kidney injury (rare, case reports)
- Tendon rupture risk (theoretical, mirroring AAS data)
- Specific watch periods:
- First 4-8 weeks: Liver enzymes (ALT/AST/GGT/bilirubin) — monitor weekly if used. Stop immediately on enzyme elevation.
- Cycle-end → 12 weeks post: LH/FSH/total + free testosterone recovery curve.
- Always: Full lipid panel pre/mid/post.
▸Interactions3 compounds
- enclomipheneSynergisticUsed as PCT to restart HPG axis post-cycle — selective ER antagonist at hypothalamus, drives LH/FSH back up.
- ostarineAvoidStacking SARMs compounds HPG suppression and hepatotoxicity — not additive in benefit, multiplicative in risk.
- rad-140AvoidSame — RAD-140 is more suppressive than LGD; stacking is the worst-of-both.