Provided is a subcutaneous injection for reducing body weight, comprising a plurality of drug-containing micelles formed of a polyoxyethylene castor oil derivative and curcumin substances encapsulated within said drug-containing micelles. The subcutaneous injection used for reducing body weight reduces body weight and visceral fat of overweight or obese individuals, and has advantages such as low injection volume, high stability, high fat tissue bioavailability, low side effects, and sustained release.