Large doses used in feed can promote pig growth, reduce fat content, and increase lean muscle mass, but consuming pork containing leptin is harmful to the human body." The residue of "lean pork" enters the human body through food, and then the human body is gradually poisoned and accumulates poison. If the intake is too large, it will produce an abnormal physiological response to the poisoning phenomenon, "lean meat essence" has been banned in China. The earliest reported case of leptin poisoning in China was caused by live pigs supplied to Hong Kong in 1998, and since then such incidents have occurred frequently, e.g., there was a batch of poisoning cases in Guangdong in 2001. Leptin once caused poisoning of several hundred people in Shanghai.

The official name of "leptin" is clenbuterol hydrochloride, or clenbuterol for short, also known as clenbuterol, aminopyralid, ampicillin, and aminodiclofenac sodium. It is a white crystalline powder with a slightly bitter taste.

Leptin is a generic term for a class of drugs, mainly adrenals, beta agonists, beta-agonists (β-agonist), which are used in the treatment of bronchial asthma, chronic bronchitis and emphysema.