Life Extension Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets supplement bottle
Life Extension

Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets

What We Researched
2 active ingredients analyzed · 8 inactive ingredients decoded · 3 brand certifications checked · 2 retailers compared · Last updated: Mar 2026
87
Product Score Good
86
Brand Score Good

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
Vitamin C (as ascorbic acid) 1000 mg 1111%
Bio-Quercetin® Proprietary Blend[providing 35% quercetin (5 mg) [from Japanese sophora concentrate (flower bud)],30% galactomannans (4 mg) [from fenugreek (seed)] 15 mg **
Bioavailability Fair

Absorption Rating

  • Vitamin C (as ascorbic acid) Fair
  • Bio-Quercetin® Proprietary Blend[providing 35% quercetin (5 mg) [from Japanese sophora concentrate (flower bud)],30% galactomannans (4 mg) [from fenugreek (seed)] Fair
Other Ingredients Excellent

Fillers & Additives

  • Microcrystalline Cellulose
  • Coating (Purified Water, Hypromellose, Glycerin)
  • Stearic Acid
  • Croscarmellose Sodium
  • Vegetable Stearate
  • Silica
  • Sunflower Lecithin
  • Sunflower Oil
Efficacy Excellent

Dosage Analysis

  • Vitamin C (as ascorbic acid) 1000 mg Effective

Supplement Facts

Ingredient Amount % Daily Value
Vitamin C (as ascorbic acid) 1000 mg 1111%
Bio-Quercetin® Proprietary Blend[providing 35% quercetin (5 mg) [from Japanese sophora concentrate (flower bud)],30% galactomannans (4 mg) [from fenugreek (seed)] 15 mg **

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Microcrystalline Cellulose Safe

Adds bulk to small-dose supplements to make tablets/capsules a manageable size.

Coating (Purified Water, Hypromellose, Glycerin) Safe

It is used to coat tablets or capsules.

Stearic Acid Safe

Helps ingredients flow smoothly through manufacturing equipment.

Croscarmellose Sodium Safe

Helps tablets break apart and dissolve quickly in the stomach.

Vegetable Stearate Safe

Prevents ingredients from sticking to equipment.

Silica Safe

Prevents ingredients from clumping and improves powder flow.

Sunflower Lecithin Safe

Helps mix oil and water-based ingredients. Allergen-free alternative to soy lecithin.

Sunflower Oil Safe

Helps dissolve and absorb fat-soluble vitamins.

Price Comparison

Price History

Tracked across major retailers. Updated periodically.

$24$23$22$21$20 Mar 12 $22.00
iHerb

Prices shown at time of last check. Click a retailer to see current price. GoodSupp is not affiliated with any retailer.

Brand Trust Report
Life Extension

Founded 1980 · Fort Lauderdale, Florida, USA · 352 products · lifeextension.com

Certifications

3 certifications
Consumerlab Verified Source
Fda Gmp Inspections Verified Source
Nsf Gmp Verified Source

Transparency

4 claims
Third Party Testing Claim — Verified Source
Coa Availability — Verified Source
Testing Lab Disclosure — Claimed

Violation History

2 incidents
Prop 65 Lead2018-04-13Source
Fda Warning Making drug claims for dietary supplements, suggesting they can treat, mitigate, or prevent diseases such as breast cancer and Alzheimer's.2017-02-01Source
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Frequently Asked Questions
Is Life Extension Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets a good supplement?

Life Extension Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets received a product quality score of 87/100 in GoodSupp's independent analysis, indicating strong overall quality. The product contains 2 active ingredients All 8 inactive ingredients (fillers, binders, capsule materials) are rated safe — a clean formulation with no flagged additives. The manufacturer, Life Extension, holds a brand trust score of 86/100 with 3 verified certifications including Consumerlab, Fda Gmp Inspections, Nsf Gmp.

What are the ingredients in Life Extension Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets?

Life Extension Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets contains 2 active ingredients: Vitamin C (as ascorbic acid) (1000 mg), Bio-Quercetin® Proprietary Blend[providing 35% quercetin (5 mg) [from Japanese sophora concentrate (flower bud)],30% galactomannans (4 mg) [from fenugreek (seed)] (15 mg). Notable high-dose ingredients include Vitamin C at 1111% DV. Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Life Extension Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets safe to take?

Life Extension Vitamin C and Bio-Quercetin, 250 Vegetarian Tablets has been analyzed for ingredient safety across all its components. All 8 inactive ingredients — including capsule materials, fillers, and binders — are rated safe based on regulatory data and published safety research. This is a clean formulation with no controversial additives. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Life Extension a trustworthy supplement brand?

Life Extension receives a brand trust score of 86/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1980 and headquartered in Fort Lauderdale, Florida, USA, the company offers 352 products in their lineup. They hold 3 verified certifications including Consumerlab, Fda Gmp Inspections, Nsf Gmp. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Life Extension has 2 historical regulatory incidents on record, which are factored into the trust score.

How much vitamin d3 should i take daily?

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

What does vitamin d do?

This is an important question for supplement consumers. The dietary supplement industry is largely self-regulated, which means product quality, ingredient transparency, and safety practices vary significantly between brands and products. The most reliable way to evaluate any supplement is to check for third-party testing certifications, review the full ingredient list and dosages, and research the brand's regulatory track record. GoodSupp's database of over 250,000 analyzed products provides independent quality scores, ingredient safety ratings, and brand trust reports to help you make evidence-based decisions.

How much vitamin d3 per day for a woman?

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

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Disclaimer: GoodSupp provides independent supplement quality analysis for informational purposes only. Scores are generated algorithmically based on ingredient profiles, brand certifications, and public records. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Product data is sourced from manufacturer labels and public databases. GoodSupp is not affiliated with any supplement brand.