Many misconceptions exist about what can help prevent hair loss, one of these being that lack of sexual activity will automatically prevent hair loss. While a proven direct correlation exists between increased frequency of ejaculation and increased levels of DHT, as shown in a recent study by Harvard Medical School , the study suggests that ejaculation frequency may be a sign, rather than a cause, of higher DHT levels.  Another study shows that although sexual arousal and masturbation-induced orgasm increase testosterone concentration around orgasm, they reduce testosterone concentration on average (especially before abstinence) and because about 5% of testosterone is converted to DHT, ejaculation does not elevate DHT levels. 
In cases of severe hair loss, limited success has been achieved by using the corticosteroids clobetasol or fluocinonide , corticosteroid injections, or cream. The cream is not as effective and it takes longer in order to see results. Steroid injections are commonly used in sites where the areas of hair loss on the head are small or especially where eyebrow hair has been lost. Whether they are effective is uncertain. Some other medications that have been used are minoxidil , Elocon (mometasone) ointment (steroid cream), irritants (anthralin or topical coal tar), and topical immunotherapy ciclosporin , sometimes in different combinations. Topical corticosteroids frequently fail to enter the skin deeply enough to affect the hair bulbs, which are the treatment target,  and small lesions typically also regrow spontaneously. Oral corticosteroids decrease the hair loss, but only for the period during which they are taken, and these drugs can cause serious side effects . 
Androgenic Alopecia - Androgenetic
Androgenetic alopecia In men, or male pattern baldness, is recognized increasingly as a physically and psychologically harmful medical condition. Androgenetic alopecia affects at least half of white men by the age of 50 years. Although androgenetic alopecia does not appear to cause direct physical harm, hair loss can result in physical harm because hair protects against sunburn, cold, mechanical injury, and ultraviolet light. Hair loss also can psychologically affect the balding individual and can Influence others' perceptions of him. A progressive condition, male pattern baldness is known to depend on the presence of the androgen dihydrotestosterone - DHT - and on a genetic predisposition for this condition. Medicines, hair transplantation, and cosmetic aids have been used to manage male pattern baldness. Two US Food and Drug Administration-approved hair-loss drugs - the potassium channel opener minoxidil and the dihydrotestosterone synthesis inhibitor finasteride -- are somewhat effective for controlling male pattern baldness with long-term daily use. Regardless of which treatment is chosen for alopecia, defining and addressing the patient's expectations regarding therapy are paramount in determining outcome.