Drug Information

Allopurinol is a xanthine oxidase inhibitor used to prevent gout and to lower blood levels of uric acid in certain people taking drugs for cancer.

Common brand names:


Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • none

Reduce Side Effects

  • High-Protein

    Compared with people on high-protein diets, people on low-protein diets excrete less allopurinol, resulting in a threefold increase in the time it takes for the drug to be removed from the body.1 Vegetarians and those who eat low-protein diets (20 grams of protein a day or less) should discuss this possible interaction with their healthcare practitioner before taking allopurinol.

    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Support Medicine

  • L-Tryptophan

    In a preliminary study, seven of eight individuals with severe mental depression showed improvement when they took L-tryptophan and allopurinol;3 of these seven, five experienced full remission. Controlled research is necessary to determine whether this combination might be more effective for severe depression than standard treatment.

Reduces Effectiveness

  • none

Potential Negative Interaction

  • none

Explanation Required 

  • L-Carnitine

    People who have Duchenne muscular dystrophy have low levels of L-carnitine in their muscles. Allopurinol restores L-carnitine to normal levels, resulting in improved muscle strength.4 Whether L-carnitine supplementation might improve this effect of allopurinol has not been investigated.

  • Vitamin D

    Individuals with gout have low blood concentration of the active form of vitamin D (1,25 dihydroxycholecalciferol), and allopurinol corrects this problem.5

The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.


1. Murrell GA, Rapeport WG. Clinical pharmacokinetics of allopurinol. Clin Pharmacokinet 1986;11:343-53.

2. Murrell GA, Rapeport WG. Clinical pharmacokinetics of allopurinol. Clin Pharmacokinet 1986;11:343-53.

3. Stern SL, Mendels J. Drug combinations in the treatment of refractory depression: a review. J Clin Psychiatry 1981;42:368-73.

4. Camina F, Novo-Rodriguez MI, Rodriguez-Segade S, Castro-Gago M. Purine and carnitine metabolism in muscle of patients with Duchenne muscular dystrophy. Clin Chim Acta 1995;243:151-64.

5. Takahashi S, Yamamoto T, Moriwaki Y, et al. Decreased serum concentrations of 1, 25 (OH)2-vitamin D3 in patients with gout. Metabolism 1998;47:336-8.