Hello Rajesh, Anabolic steroids have been implicated for gaining weight and building of muscles. Though they initially cause weight gain & muscle bulk, they result in lots of side effects. Long term side effects of these steroids include high blood pressure, electrolyte imbalance, headache, muscle weakness, puffiness of face, thinning and easy bruising of skin, glaucoma, cataracts, peptic ulceration, worsening of diabetes, mood swings, personality changes, etc. So, before choosing any such tablet or health supplement, it is advisable to consult your family physician once. Moreover, you should not compromise on routine healthy food such as: 1. Consume more of natural diet like fresh fruits, green vegetables, milk, eggs, wheat, etc. 2. Avoid oily and junk food. 3. Stay away from smoking & alcohol. Despite these measures, if you experience difficulty, it will be better to rule other causes of underweight. Investigations like complete blood count, thyroid profile, estimation of blood sugar level will be helpful to rule out any chronic infection, hormonal and metabolic causes. Wishing you a healthy life. Take care.