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It may be possible to reduce man boobs without surgery. This depends on how big the man boobs are, and how much percent body fat you have. Generally gynecomastia is found in more obese individuals, so weight loss can sometimes help. However if there is excess skin, then weight loss will not help. The man boob reduction can sometimes be done with liposuction alone, or may require direct breast tissue removal or even skin reduction depending on the body type.
First visit with your primary care physician to confirm there is no medical cause for your excessive breast tissue such as tumor, endocrine (glands), genetic or medications. Second, consider weight loss if you are at all overweight. Losing fat all over your body will also mean losing fat in your breasts. In addition, testosterone is converted to estrogen in fat cells, so losing weight can theoretically help decrease the amount of estrogen that can contribute to male breast enlargement. Finally, meet with a plastic surgeon to discuss less invasive techniques to treat gynecomastia such as liposuction or one of the many variations, styles, techniques and technologies of liposuction. Finally, ask about surgery as you may find it more acceptable than you thought as the scars are not noticeable and the recovery is just as quick as less invasive techniques.