For immune support and antioxidant defense, this gives you a strong dose — 1,000 mg of **Vitamin C** per capsule, and the label suggests two daily for 2,000 mg total, right at the top of the clinical range. Even one capsule puts you at a fully effective level. The formula also includes 200 mg of **citrus bioflavonoids**, which may support absorption.
Ester-C is marketed as a gentler, better-absorbed form of vitamin C, but the research behind those claims is limited. Independent studies haven't shown a clear advantage in terms of blood levels or health outcomes, so the premium you're paying for the Ester-C form may not translate into better results for you.
The capsules use gelatin, so they're not suitable if you follow a vegetarian or vegan diet. At the full two-capsule dose, you're at the 2,000 mg tolerable upper limit — generally safe, but worth knowing if you also get vitamin C from other sources throughout the day.
BioStacks
Other Ingredients (2)
Magnesium StearateLubricant
A salt of stearic acid used as a lubricant in tablet and capsule production
GelatinCapsule
Protein derived from collagen, used in traditional capsule shells
How to Take It
Take it anytime
Ester-C is buffered (calcium-ascorbate-based), so it's less acidic than plain ascorbic acid — but evidence it's meaningfully gentler is thin. Timing still doesn't matter.
With or without food
On the label
Suggested use: As a dietary supplement for adults, take one (1) capsule twice a day, preferably with meals or as directed by a healthcare practitioner.
General guidance based on the ingredients, not a substitute for the label or your doctor.
Price Check
$14.24
Cheaper than 68% of 375 vitamin C supplements
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Sources & Scoring
Nutrient data (RDA, UL, and safety thresholds) sourced from the NIH Office of Dietary Supplements and the National Academies Dietary Reference Intakes (DRI).
This is not medical advice. Consult a healthcare provider before making changes to your supplement routine.
The score analyzes what's on the label: ingredient doses vs. studied ranges, chemical forms, evidence levels, and known interactions. It does not verify label accuracy or test for contaminants — for that, look for third-party certifications like USP or NSF.