Drug Information

Losartan is used alone or in combination with hydrochlorothiazide (Hyzaar®) in the treatment of high blood pressure. It is a type of drug called an angiotensin II receptor antagonist.

Common brand names:


Summary of Interactions with Vitamins, Herbs, & Foods

Types of interactions: Beneficial Adverse Check

Replenish Depleted Nutrients

  • Zinc
    Losartan has been reported to increase urinary excretion of zinc, but the clinical significance of that finding is not certain.1
    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Reduce Side Effects

  • none

Support Medicine

  • none

Reduces Effectiveness

  • Grapefruit
    Ingestion of grapefruit or grapefruit juice may increase the absorption of losartan by inhibiting an enzyme that breaks down the drug in the intestinal tract 2. Consumption of grapefruit products could therefore increase both the effectiveness and the adverse effects of this drug. People taking losartan should not use grapefruit products without medical supervision.
    The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.

Potential Negative Interaction

  • Potassium
    Losartan has caused significant increases in blood potassium levels. Potassium supplements, potassium-containing salt substitutes (No Salt, Morton Salt Substitute, and others), and even high-potassium foods (including Noni juice) should be avoided by those taking losartan, unless directed otherwise by their doctor.3

Explanation Required 

  • none

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. Braun LA, Rosenfeldt F. Pharmaco-nutrient interactions - a systematic review of zinc and antihypertensive therapy.Int J Clin Pract 2013;67:717–25.

2. Fuhr U. Drug interactions with grapefruit juice. Extent, probable mechanism and clinical relevance. Drug Saf 1998;18:251-72.

3. Noni. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on September 13, 2011