For daily immune and antioxidant support, two capsules give you 1,000 mg of **Vitamin C** — right in the middle of the clinical range (250–2,000 mg) and a well-supported dose. You can also take just one capsule on lighter days and still get 500 mg, which is above the clinical minimum. Each capsule adds 200 mg of **citrus bioflavonoids** as a modest complement.
Ester-C is positioned as a premium, stomach-friendly form of vitamin C, but the clinical evidence supporting meaningful absorption advantages is thin. It works fine as a vitamin C source, but you shouldn't expect a significant edge from the form itself.
At the full two-capsule dose, you're well under the 2,000 mg tolerable upper limit, which gives you room if you get vitamin C from other sources too. The capsules are gelatin-based, so they're not suitable for vegetarian or vegan diets.
BioStacks
Other Ingredients (4)
GelatinCapsule
Protein derived from collagen, used in traditional capsule shells
Microcrystalline CelluloseBinder
Plant-derived cellulose used as a binder and filler in supplements
Microcrystalline CelluloseBinder
Plant-derived cellulose used as a binder and filler in supplements
Stearic AcidLubricant
Saturated fatty acid used as tablet lubricant
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
Split into 2 doses across the day
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
$13.27
Cheaper than 73% of 375 vitamin C supplements
Track this supplement in your stack
Get personalized insights, interactions, and coverage recommendations.
Get Started FreeSimilar Supplements
NOW
C-500 Calcium Ascorbate-C
🛡️ for Immune
80
ProCaps
Vitamin C 500 Complex
🛡️ for Immune
77
Carlyle
Vitamin C Buffered 2000 mg with Bioflavonoids & Rose Hips
🦷 for Dental
67
Nature's Bounty
Ester-C®, Maximum Strength, 1,000 mg, 120 Vegetarian Coated Tablets
🛡️ for Immune
63
Jarrow Formulas
Buffered Vitamin C + Citrus Bioflavonoids 750 mg
🛡️ for Immune
60
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.