Metribolone (MT) is a very potent, reasonably toxic, non-aromatizing steroid.  It binds so strongly to the AR (androgen receptor) that it is often used in studies on other androgens to measure how strongly they bind. In other words, this stuff binds onto the AR receptor so strongly t.hat it is pretty much the benchmark for that quality. It’s simply the oral version of Trenbolone Acetate which has undergone modification to become orally active, via the addition of a 17-alph-methyl group). 

Metribolone Profile

• [17beta-Hydroxy-17-methylestra-4,9,11-trien-3-one]
• Molecular Weight: 284.3974
• Formula: C19H24O2
• Melting Point: N/A
• Manufacturer: Negma (never released), Underground Labs
• Effective dose: 500-750mcgs/day
• Active Life: 4-6hours
• Detection Time: Unknown (never tested in humans)
• Anabolic/Androgenic Ratio (estimated):12,000+/6,000+