Prevention of male pattern hair loss or androgenic alopecia in 20’s is premature obviously. But there is nothing much that can be done to prevent this. Once the genes are passed onto you, then you will. Early presentation of genes will lead to early baldness, there are medications to be given. You can consult your dermatologist, there are lotions to be given to grow your hair and these tablets can be given under the prescription only. You cannot take it over the counter. You can be helped. Atleast you can save whatever hairs you already have. Also prevent further shedding of the hair and as much as possible, we can help you to grow your hair back also. But t is a continuous long term treated. The minute you stop, you can loose back your hair.