And btw I haven't read about health and general nutrition for a while (in depth), but these are the rough reasons off the top of my head why you shouldn't take steroids (like any other drug). I'm not saying they're bad or comparing them to anything.
- Firstly in pill form which are the most accessible forms of steroids they are very bad for your liver. Something to do with the liver metabolizing the drug, this process causes liver damage and stress. Alcohol and paracetamol and most other over the counter drugs cause liver damage also. Milkthistle is usually used to offer some protection.
- DHT is a chemical (dihydrotestosterone). Steroid use can increase levels of this chemical which is a problem for hair folicals at the scalp or anyone that has hair loss in their genes. This isn't reversed either.
- Testosterone secreted by your testicles. When using steroids your body significantly reduces it's own production of testosterone or shuts it off completely, this is because of the extra Testosterone like chemicals you are taking in steroid form. This is a problem when you come OFF the steroids, you have to take more drugs to try and kick start your own production.
- Infertility. Can't remember how but know it can cause infertility, probably linked to above.
- Moobs (gynecomastia) and lactating (milk). Men naturally have low levels of estrogen (female hormone). A side effect of most steroids is high levels of estrogen in the body, I believe the body increase its naturally low level of estrogen to match the testosterone levels in your body (could be wrong).
Certain areas (cells) in the body are more receptive to the estrogen hormone (such as the breasts), and this basically causes fat storage in these areas. You need to take forms of anti-estrogen drugs to block the cells responding to estrogen, this needs to be done for weeks after you complete your "course".
Not sure how it causes lactating, but I think the estrogen activates men's milk glands in the breast and there for producting of your very own milk.