Weight-loss injections linked to malnutrition risks in long-term patients

New weight-loss injections such as semaglutide and tirzepatide may help patients shed pounds, but long-term use could raise the risk of malnutrition. A recent study found that 38% of users showed signs of nutrient deficiencies, far higher than in those not taking the drugs. Experts now warn that dietary guidance is essential for anyone prescribed these treatments.

Researchers analysed six clinical trials involving nearly 481,000 participants using GLP-1 receptor agonists. After six months, 7.5% developed vitamin D deficiency, rising to 13.6% after a year. Many also had low iron levels, with ferritin readings 26 to 30% lower than in patients on other diabetes medications.

The drugs work by suppressing appetite, leading to reduced food intake. Over time, this can cause shortages in calcium, iron, protein, and vitamins like thiamine and cobalamin. Muscle loss and dehydration may follow, as the injections also reduce thirst.

German medical guidelines recommend these treatments only for patients with a BMI of 30 or above—or 27 with related health conditions. They stress that use must be combined with diet, exercise, and behavioural therapy. However, no specific monitoring for nutrient deficiencies is currently outlined.

Patients on these weight-loss drugs face a higher risk of malnutrition without proper dietary support. Doctors are advised to provide counselling and highlight potential deficiencies. The findings suggest that long-term users may need regular nutrient checks to avoid health complications.