Is it okai to drink musclemilk or sum kind to gain help gain muscles?

Yes. It is a product based on whey protein.

Just make sure that you can tolerate milk proteins. Some of us are not only lactose intolerant but also milk protein intolerant. This causes bloating and diarrhea. But usually doses of less than 40 grams per day are OK for most of us, specially if you take a digestive enzyme supplement with it.

Keep in mind that a study done in HIV using whey protein did not see any gains in muscle or weight compared to placebo. People on the supplement tended to compensate by eating less, so their total caloric intake stayed the same. So, if you want to gain weight, drink it with a meal and not between meals.

Interestingly, whey protein increases glutathione blood levels (your body's own antioxidant). The study saw a small increase in CD4 cells in patients using the supplement.

Nelson

Reference: Evaluation of high-protein supplementation in weight-stable HIV-positive subjects with a history of weight loss: a randomized, double-blind, multicenter trial