Coated tablet · 500 mg · The yellow box

Ester-C 500 mg 24 Hour Tablets

4.7 (8,901) 4.7 out of 5 from 8,901 ratings

$6.97
16¢ a serving · 45 servings

2 tablets = 1,000 mg of vitamin C as Ester-C calcium ascorbate, with 204 mg citrus bioflavonoids.

Bottle size90 tablets$6.97 · 16¢ a serving4 × 90 tablets$26.54 · 15¢ a serving

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About this formula

The same Ester-C calcium ascorbate in a half-size coated tablet. The box asks adults for two tablets a day, preferably with a meal, which gives you 1,000 mg of vitamin C and 204 mg of the C-Sorb citrus bioflavonoid complex per serving.

Pick it if the 1000 mg tablet feels large, or if you like to take one with breakfast and one later in the day. The 24 Hour name refers to the white blood cell study described in our buffered vitamin C article, funding included.

How to take it

For adults, take two (2) tablets daily, preferably with a meal.

Two tablets of Ester-C 500 mg 24 Hour Tablets make the serving, so the 90 tablets bottle lasts 45 days.

Ingredients and free-from

Citrus Bioflavonoid Complex (Citrus spp.) (peel and fruit), Sweet Orange, Tangerine, Lime, Lemon, Acerola Extract, Rutin, Hesperidin Complex (Citrus spp.) (peel), Naturally Occurring Vitamin C Metabolites.

Other ingredients: Vegetable Cellulose. Contains <2% of: Calcium Silicate, Natural Palm Leaf Glaze, Vegetable Magnesium Stearate, Vegetable Stearic Acid.

Non-GMO, No milk, No lactose, No soy, No gluten, No wheat, No yeast, No starch, No sugar, No fish, No artificial color, No artificial flavor, No artificial sweetener, Sodium free, Vegetarian friendly.

Supplement Facts

The panel of Ester-C 500 mg 24 Hour Tablets

Supplement FactsServing Size 2 Tablets
Amount Per Serving	Amount	%Daily Value
Vitamin C(as Ester-C® Calcium Ascorbate)	1,000 mg	1,111%
Calcium(as Ester-C® Calcium Ascorbate)	110 mg	8%
C-Sorb™ Citrus Bioflavonoid Complex	204 mg	**

Citrus Bioflavonoid Complex (Citrus spp.) (peel and fruit), Sweet Orange, Tangerine, Lime, Lemon, Acerola Extract, Rutin, Hesperidin Complex (Citrus spp.) (peel), Naturally Occurring Vitamin C Metabolites

**Daily Value not established.

Reading this panel

On the Ester-C 500 mg 24 Hour Tablets panel the serving is 2 tablets, each holding 500 mg, the vitamin C line reads 1,000 mg (1,111% of the 90 mg Daily Value), calcium reads 110 mg, and the c-sorb™ citrus bioflavonoid complex reads 204 mg with two asterisks, because no Daily Value exists for it.

Read the full label guide

Your daily vitamin C

How one serving compares with what you need

One serving of Ester-C 500 mg 24 Hour Tablets gives you 1,000 mg of vitamin C, against an NIH Recommended Dietary Allowance of 75 mg a day for adult women and 90 mg for men (35 mg more for smokers) and an upper limit of 2,000 mg a day from food and supplements together.

Work out your own figure

Sources

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Vitamin C: Fact Sheet for Health Professionals, NIH Office of Dietary Supplements. Read October 25, 2026.
Daily Value on the Nutrition and Supplement Facts Labels, U.S. Food and Drug Administration. Read October 25, 2026.
Dietary Supplement Labeling Guide: Chapter VI, Claims, U.S. Food and Drug Administration. Read October 25, 2026.
Determination of plasma and leukocyte vitamin C concentrations in a randomized, double-blind, placebo-controlled trial with Ester-C (Mitmesser et al., SpringerPlus, 2016), PubMed Central, National Library of Medicine. Read October 25, 2026.

Every source is linked on our page How we keep the facts current.

The range

Ester-C 500 mg 24 Hour Tablets next to the rest of the Ester-C family

How Ester-C 500 mg 24 Hour Tablets compares with the other Ester-C formulas
Formula	Form	Serving	Bioflavonoids	Calcium	Vegetarian	Bottle sizes	Per serving, from
Vitamin C 1000 mg Coated Tablets	Coated tablet	1 × 1000 mg	102 mg	110 mg	Yes	90, 120, 2 × 120	13¢
500 mg 24 Hour Tablets	Coated tablet	2 × 500 mg	204 mg	110 mg	Yes	90, 4 × 90	15¢
500 mg with Citrus Bioflavonoids Capsules	Capsule	2 × 500 mg	400 mg	110 mg	No	60, 120, 240, 300	19¢
1000 mg with Citrus Bioflavonoids Capsules	Capsule	1 × 1000 mg	200 mg	108 mg	No	90, 105, 3 × 90	21¢
1000 mg with Citrus Bioflavonoids Vegetarian Tablets	Vegetarian tablet	1 × 1000 mg	200 mg	110 mg	Yes	45, 120, 180, 2 × 180	17¢
500 mg with Citrus Bioflavonoids Vegetarian Tablets	Vegetarian tablet	2 × 500 mg	400 mg	110 mg	Yes	90, 450	16¢

Questions about Ester-C 500 mg 24 Hour Tablets

How do you take Ester-C 500 mg 24 Hour Tablets?

The pack says: "For adults, take two (2) tablets daily, preferably with a meal."

How long does a bottle of Ester-C 500 mg 24 Hour Tablets last you?

At one serving a day, 90 tablets last 45 days, 4 × 90 tablets last 180 days. The largest, 4 × 90 tablets, works out to 15¢ a serving.

What else is in Ester-C 500 mg 24 Hour Tablets besides vitamin C?

Each serving of Ester-C 500 mg 24 Hour Tablets also holds calcium 110 mg and c-sorb™ citrus bioflavonoid complex 204 mg.

Is Ester-C 500 mg 24 Hour Tablets vegetarian?

Yes, the Ester-C 500 mg 24 Hour Tablets pack labels it vegetarian friendly and lists non-gmo, no milk, no lactose, no soy, no gluten.

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