The key to this stuff is some of it will be androstenedione/androstenediol by the time it gets to the other side of your skin, a good deal of conversion takes place while it passes through, some of it will likely even convert to testosterone by the time is penetrates the skin. The key to this is that the you apply the product to parts of the skin that have high concentrations of the enzymes needed to make the conversions. Where are the highest concentrations? Anywhere where you got acne in puberty (or still today). Shoulders and upper back are great, i do shoulders, upper back and abdomen (abdomen cause the skin is thin so I get more penetration there, even if the penetration is more likely just DHEA, it still has its benefits and can convert in the testes). But other areas could be good too, maybe thighs or forehead/nose area, the one place I would definitely stick with is shoulders but you can experiment with other areas.