Introduction:
Weight-loss products are widely used. Their popularity increases and they are easily available. Reliable scientific studies concerning short- and long-term health effects of these products are scarce.

Objective:
The objective of the study is presentation of skin manifestations of hypersensitivity induced by selected weight-loss products. ]

Case description:
Three patients with adverse reactions after fitness products were analyzed. The first patient used Linea Detox, the second a Celsius Calypso Punch Shot energy drink, and the third received Dermostabilon injection in the area of the buttocks and fatty tissue of the thighs. All were treated in the Department of Dermatology, Venereology and Allergology at the Medical University of Gdańsk in 2011–2012. Patients were between 20–26 years old, and all were previously healthy. Hypersensitivity reactions presenting as anaphylaxis were observed in all three patients. The manifestations were dyspnea and urticaria. The onset was 1–4 days after first administration. All patients were responsive to treatment with corticosteroids and antihistamines.

Conclusions:
Caution should be taken in usage of weight loss products since they can cause severe allergic reactions to a susceptible patient. Doctors should ask patients about usage of food supplements to reveal the possible causative agent. The long-term adverse effects of these drugs are not sufficiently known and need further investigations.