Are prohormones legal

Yes, some are still legal. There are some that are legal and can actually be considered supplements and some that are just "grey area" unbanned steroids. I will list most of them below, to the best of my memory:

Legal prohormones considered supplements:

Delta-2-androst-17-one

androsterone

1-androsterone

4-androsterone

Legal hormonal considered supplements (may be anti-estrogenic or anti-cortisol)

Androst-3,5-dien-7,17-dione

7-Keto DHEA

7-OH DHEA

andrenosterone AKA 11-ketoandrostenedione

11-ketotestosterone

"grey market steroids"

2a-3a-epithio-17a-methyl-5a-androstan-17b-ol

2a, 17a-dimethyl-17b-hydroxy-5a-etiocholan -3-one

4-chloro-17a-methyl-4-ene-3,17 diol

4-chloro-17a-methyl-1,4-diene-3,17 diol

[3,2-c]pyrazole-5alpha-etioallocholane-17beta-tetrahydropyranol

13-ethyl-3methoxygona-2, 5(10)-dien-17-one

17a-methyl-1,4-Androstadiene-3,17diol