I take 10gm homeopathic weightgain supplement powder in each month since 4years. any side effects?

Not known: There are a great many "weight gain supplements" and "weight loss supplements" out there, being sold to people. It's a big industry. However, since they are not real medications and are not scientifically studied nor regulated by the fda, nobody really knows what the true effects and side effects are.

"Homeopathic"???: Not knowing what supplement you're taking, it's impossible to comment. Also, the term "homeopathic" can be misused. True homeopathic remedies are individually prescribed, & regulated by the fda via the homeopathic pharmacopoeia of the us: http://www.Hpus.Com/whatishpus.Php the powder you're using is most likely not a true homeopathic remedy, and is also not likely to be homeopathic to you either.