Supplements & Vitamins

How to shop for supplements and vitamins online

Read the Supplement Facts panel, not the front label. Check the serving size first: a "1,000mg" claim may require three capsules per serving, which changes the cost per day. Look at the form of each nutrient, since forms differ in absorption and tolerance (magnesium glycinate is generally gentler on the stomach than magnesium oxide, for example). Proprietary blends list ingredients without individual doses, which makes it impossible to know how much of each you are taking.

Look for third-party testing. The FDA does not approve supplements before sale. Seals from USP, NSF or, for athletes subject to drug testing, NSF Certified for Sport or Informed Sport indicate independent checks for contents and contaminants. A certificate of analysis from the brand is helpful but not the same as independent certification.

Watch stimulants and interactions. Thermogenic and pre-workout products often contain significant caffeine; the FDA cites 400mg a day as a level not generally associated with negative effects in healthy adults, and one ThermoLean capsule lists 200mg. Herbs like ashwagandha, berberine and St. John's wort can interact with medications. Products marketed for hormones, blood sugar or weight loss deserve a conversation with your doctor before purchase.

Endurance fuel: test before race day. Gels, chews and drink mixes vary in carbohydrate type, sodium and caffeine. Gut tolerance is personal, so buy single servings, try them on long training sessions, then buy in bulk. Check the expiration date on bulk orders.

Price per serving, not per bottle. Compare cost per day at the dose you will actually take. Ignore inflated compare-at prices, which several stores here display permanently. Subscriptions can save money but check how to cancel and whether prepaid subscriptions are refundable.

Return policies are strict. The Feed gives store credit, not cash, for opened food, and some opened supplements over $40 are final sale. NuVision and Mars By GHC make all sales final, with only damaged or defective items exchanged within 7 or 14 days respectively. Natural Cure Labs allows 60 days for unopened items with possible $3 per item fees. Photograph damaged packages on arrival.

Shipping and storage. Probiotics and some oils are heat sensitive; avoid leaving packages in summer sun. International supplement orders may be delayed or confiscated by customs, and some stores will not refund seized orders.

Which brand fits which buyer

• Runners, cyclists and triathletes testing fuel across many brands: The Feed.
• Shoppers who already take monolaurin or L-lysine and want filler-free capsules: Natural Cure Labs.
• Buyers wanting mainstream ingredients from a US company with a phone line: Nature's Fusions, asking about return terms first.
• Followers of practitioner-line brands: NuVision Health Center, knowing all sales are final.
• Label readers who avoid proprietary blends: Green Regimen, minding the caffeine dose.
• Men trying nitric oxide or shilajit stacks: Mars By GHC, accepting no returns once delivered.
• Viva Nutra, Sunleafy and Zstack Canada are small, lightly documented stores with conflicting or final-sale return terms; confirm terms by email before ordering. Obvi Canada showed only a Coming Soon page when we checked.