Deca Durabolin - I've never had a problem with my hair on this one, neither have hundreds of other guys I've talked to. The safety of this steroid, as far as hairloss is concerned, stems from the fact that 5-alpha-reductase enzyme, instead of converting it to a stronger androgen like DHT, converts it to a very mild androgen called DHN. Taken in dosages of up to 300-400 mg weekly it shouldn't produce any hairloss problems, this is due to the fact that, being a highly HPTA supressive androgen, 300-400 mg are no more androgenic than our endogenous testosterone (supressed while we are taking it) would be.. One BIG word of caution: While you are taken Deca Durabolin never ever take 5AR blockers such as Proscar/Propecia, for it would block the conversion of nandrolone to DHN in tissues such as the scalp and the prostate, resulting in hairloss and BPH, which is what we are trying to avoid taking Deca.
Above is an excerpt from one of the web sites that I use as reference for hair loss issues, treatments, etc.