you may be a young male wishing to have more muscles. It is important that you have to see a doctor internist. You will be worked up for diabetes remember skinny ang young people may have type 1 diabetes..weight loss despite eating a lot, frequent urination, always thirsty.One more thing have your thyroid hormone checked you might be hyperthyroid. We have a way to check the proper weight for height and that is the BMI or body mass index. Go see ur doctor first and dont buy any of those herbal products. If you are not diabetic nor hyperthyroid then a nutrition expert must be consulted together with a fitness expert for proper way to build muscles.