In my neighborhood health food store, they sell natural steroids. Are these supplements safe?

The health food supplement industry is unregulated. Anyone can sell anything. The majority of products sold in these stores have never been tested. Moreover, the quality of the product varies from store to store. Many of these so called natural hormones are often combined with other chemicals and then marketed as dietary supplements- otherwise the FDA will be on their arse. Hormonal products are not allowed to be sold without FDA approval and thus, whatever you buy in these  stores is probably junk, fake or counterfeit. The safest way to buy steroids is to get a prescription from a doctor. 

However, it is unlikely any decent physician will write you a prescription just so that you can build your body-otherwise the FDA will be on their arse. The FDA has been clamping down on unscrupulous doctors who write such prescription chiefly because these hormones do have many  side effects and the drugs have the potential to be abused. Best advice, avoid health food stores and stay away from steroids.  Build your body the hard and natural way-this will be safe and more gratifying.