Medications to Support Weight Gain in Nutritional Rehabilitation: What You Need to Know

In the treatment of eating disorders, nutritional rehabilitation is essential—but it can also be slow, distressing, and medically complicated. For individuals who struggle to gain weight despite structured meals and therapy, or those who experience persistent gastrointestinal discomfort, medications may be used as an adjunct to support weight restoration.

While no medication can replace adequate food intake or compassionate care, certain prescriptions may help stimulate appetite, reduce GI discomfort, and promote metabolic recovery. This blog explores evidence-based medications used to support weight gain during nutritional rehabilitation, including their roles, benefits, and cautions.

When Are Medications Used to Support Weight Gain?

Medications are not first-line interventions, but they may be helpful when:

• A patient is unable to meet caloric needs consistently, even with support

• There is extreme food-related anxiety or fear that limits intake

• GI symptoms (nausea, bloating, gastroparesis) interfere with eating

• Medical stability requires faster weight gain or appetite enhancement

• Co-occurring psychiatric conditions (e.g., depression, anxiety, ADHD) impact feeding behavior

A multidisciplinary team—including a medical provider, therapist, and dietitian—should assess when medications are appropriate and how they fit into a holistic care plan.

Medications Commonly Used in Nutritional Rehabilitation

1. Cyproheptadine (Periactin)

• Class: Antihistamine with appetite-stimulating properties

• Mechanism: Blocks serotonin and histamine receptors; increases appetite and may reduce early satiety

• Common Use: Especially helpful in younger patients or those with ARFID, early satiety, or low appetite

Evidence: Studies in pediatric and adolescent populations show moderate effectiveness in increasing appetite and weight gain (Luscombe et al., 2010).

Cautions: Can cause sedation, dry mouth, or dizziness; not recommended in those with a history of angle-closure glaucoma.

2. Mirtazapine (Remeron)

• Class: Atypical antidepressant (noradrenergic and specific serotonergic)

• Mechanism: Increases appetite and reduces nausea; has anti-anxiety and sleep-promoting properties

• Common Use: For patients with co-occurring depression, anxiety, insomnia, or appetite suppression

Evidence: Known to cause weight gain in non-eating disorder populations; used cautiously in eating disorder treatment to address mood and promote intake (Agras et al., 2004).

Cautions: May increase cholesterol and triglycerides; monitor for sedation and mood shifts.

3. Olanzapine (Zyprexa)

• Class: Atypical antipsychotic

• Mechanism: Reduces obsessive-compulsive thoughts, anxiety, and hyperactivity; associated with increased weight and decreased agitation

• Common Use: For individuals with severe anorexia nervosa, high levels of fear around food, or co-occurring OCD traits

Evidence: Randomized controlled trials show modest weight gain and reduced anxiety around meals (Attia et al., 2011; Norris et al., 2011).

Cautions: Risk of metabolic syndrome, sedation, and rare extrapyramidal symptoms; used at low doses and monitored carefully.

4. Megestrol Acetate (Megace)

• Class: Progestational agent

• Mechanism: Potent appetite stimulant; increases fat mass

• Common Use: Sometimes used in cancer-related cachexia or AIDS-related wasting; occasionally considered in eating disorder patients with severe malnutrition

Evidence: Not commonly used in adolescents or long-term treatment due to risk of adrenal suppression and blood clots

Cautions: Significant side effects; rarely first-line in ED care due to hormonal and thrombotic risks

5. Dronabinol (Marinol)

• Class: Synthetic cannabinoid (THC)

• Mechanism: Stimulates appetite, reduces nausea

• Common Use: Sometimes used in ARFID or in patients with severe anxiety, nausea, or poor intake

Evidence: Modest efficacy in certain populations; limited evidence in eating disorders. May be helpful for short-term appetite support, particularly in medically supervised settings.

Cautions: Can cause dysphoria, increased anxiety, or dependence in some patients; controversial in adolescents

6. Metoclopramide (Reglan)

• Class: Prokinetic agent

• Mechanism: Enhances gastric motility and emptying

• Common Use: For patients with gastroparesis, early satiety, or severe bloating that interferes with intake

Evidence: Often used in short-term settings to manage symptoms during early refeeding

Cautions: Rare risk of tardive dyskinesia with long-term use; typically prescribed for 4–12 weeks under careful supervision

Important Considerations When Using Medications for Weight Gain

• Medications are adjuncts, not replacements for structured meals and psychological support

• Most are used off-label in eating disorder care; require informed consent and monitoring

• The choice of medication should be individualized, based on medical status, psychiatric symptoms, and nutritional needs

• Appetite stimulation does not guarantee intake if fear, rigidity, or trauma blocks eating—psychotherapy remains essential

Are There Risks to Using Medications for Weight Gain?

Yes. Risks include:

• Metabolic side effects (e.g., elevated lipids, insulin resistance)

• Sedation or cognitive blunting

• Dependency on appetite stimulation to eat

• Masking of emotional or trauma-related food avoidance

Careful risk-benefit analysis is needed, especially in adolescents and individuals with a history of medication sensitivity or polypharmacy.

Final Thoughts

In nutritional rehabilitation, food is the most important medicine. But for some, medications can help reduce barriers, stimulate appetite, or relieve distress enough to allow for consistent eating and healing.

The goal is not to rely on medications forever—but to use them thoughtfully and temporarily as tools in the larger process of reconnecting with food, body, and self.

When chosen carefully and used alongside therapy and nutrition support, these medications can help individuals move through the hardest parts of recovery toward stability, nourishment, and long-term healing.

References

• Attia, E., et al. (2011). Olanzapine versus placebo in outpatients with anorexia nervosa. Psychological Medicine, 41(10), 2177–2182.

• Norris, M. L., et al. (2011). Olanzapine use in children and adolescents with anorexia nervosa: A retrospective study. International Journal of Eating Disorders, 44(1), 29–35.

• Luscombe, G. M., et al. (2010). Cyproheptadine for appetite and weight improvement in children. Journal of Paediatrics and Child Health, 46(6), 356–360.

• Agras, W. S., et al. (2004). Mirtazapine and nutritional counseling in the treatment of anorexia nervosa. International Journal of Eating Disorders, 35(1), 72–85.

• Mehler, P. S., & Andersen, A. E. (2015). Eating Disorders: A Guide to Medical Care and Complications. Johns Hopkins University Press.