Head-to-Head Comparison Table
| Parameter | RAD-140 (Testolone) | LGD-4033 (Ligandrol) |
|---|---|---|
| Developer | Radius Health | Ligand / Viking Therapeutics |
| AR binding (Ki) | ~7 nM | ~1 nM (higher affinity) |
| Anabolic:Androgenic ratio | ~89:1 | ~500:1 (more selective) |
| Aromatization | None | None |
| 5α-reduction | None | None |
| Max clinical stage | Phase I (oncology) | Phase II (muscle, hip fracture) |
| Human lean mass data | No Phase II lean mass data | +1.21 kg at 1 mg/day/21 days |
| Neuroprotection data | Yes (3+ published papers) | Minimal |
| Half-life (rodent) | ~16–18h | ~24–36h |
| WADA status | S1 Prohibited | S1 Prohibited |
When to Choose RAD-140
- Neuroprotection research: RAD-140 has the most published neuroprotection data of any SARM — Aβ toxicity protection, HER2+ cancer neuroprotection, spatial memory in aged rats
- AR selectivity profiling: Its ~89:1 A:A ratio makes it useful in comparative selectivity studies
- ER+ breast cancer biology: Phase I conducted in ER+/HER2+ breast cancer — relevant research context
- Shorter half-life protocols: ~16–18h vs 24–36h for LGD-4033; useful for more frequent dosing interval designs
When to Choose LGD-4033
- Muscle wasting models: Basaria Phase II data provides human PK and efficacy benchmarks at 1 mg/day; highest lean mass effect per dose of any SARM in human data
- Hip fracture/rehabilitation models: Viking Phase II data directly relevant to musculoskeletal rehabilitation research
- Once-daily chronic protocols: Longer half-life (~24–36h) is better suited to once-daily steady-state dosing
- Prostate safety models: Higher A:A ratio (~500:1) means more prostate-sparing in comparative androgenic side effect studies
Combination Research Designs
Some research designs may combine RAD-140 and LGD-4033 to probe complementary aspects of AR biology — e.g., neuroprotection (RAD-140) in a model that also requires lean mass readouts (LGD-4033 benchmarks). Mechanistically, both bind the same receptor; combined use in single models should account for competitive binding at AR.