Most of the times we read that primo's ratio is over 6:1. Here in this study I think we can conclude that it barely reaches 2:1, if anything...

Steroids (1966) volume 8, issue 2, page 216

By subcutaneous injection with castrated rats using levator ani as indicator of anabolic activity:

Testosterone Propionate (standard) : 100

1-Tesosterone: 210

Methenolone (primobolan): 88


In this study, 1-test is quite a bit more anabolic then primo. It is very important to note however that this is by injection, and not by oral administration

Androgenic activity is determined by seminal vesicle and ventral prostate weight. How these relate to MPB, I can't say exactly

Testosterone Prop: 100(SV) 100 (VP)

1-Testsosterone: 135(SV) 123(VP)

Methenolone: 44(SV) 57(57)