Endurance Products

Endur-C SR 500mg, 90 Tablets

Endur-C SR 500mg is a sustained-release vitamin C (ascorbic acid) supplement from Endurance Products, designed to support immune function and antioxidant defenses.

4.8 across 1 sources

May be a fit for

  • Adults seeking sustained-release vitamin C absorption throughout the day
  • Individuals supporting collagen synthesis with time-released ascorbic acid
  • Those with sensitive stomachs who may find standard vitamin C difficult to tolerate
$16.99

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TabletsFormat
90 TabletsPack size
The essentials

A closer look.

Endur-C SR 500mg is a sustained-release vitamin C (ascorbic acid) supplement from Endurance Products, designed to support immune function and antioxidant defenses. The slow-release wax matrix tablet delivers 500mg of vitamin C gradually over several hours, helping maintain steadier plasma levels compared to standard immediate-release forms. It's well-suited for those seeking consistent vitamin C support throughout the day.

Why It's Worth Considering: The sustained-release delivery format is intended to reduce the rapid excretion common with high-dose ascorbic acid, potentially improving retention and tolerability for sensitive individuals.

The Apotheca perspective

50+ signals. A clearer standard.

Our curation and trust scoring bring together manufacturing, testing, research, practitioner insight and reviews from across the web.

76OUT OF 100
Manufacturing5757
Lab verification6565
Transparency5858

Our score is an editorial assessment, not a product certification or a guarantee of results.

Inside the formula

Product details

Who it may suit

May be a fit for

  • Adults seeking sustained-release vitamin C absorption throughout the day
  • Individuals supporting collagen synthesis with time-released ascorbic acid
  • Those with sensitive stomachs who may find standard vitamin C difficult to tolerate
  • Active adults looking to maintain antioxidant status with steady 500mg vitamin C delivery

Considerations

  • Known allergy to any ingredient (check label)
  • Currently pregnant or breastfeeding (consult healthcare provider)
  • Taking prescription medications (check for interactions)
  • Under 18 years of age (unless recommended by pediatrician)
From across the web

Real reviews. A wider perspective.

Customer reviews, social conversations and expert insights, with every source in view.

4.8/5Aggregate source rating
Marketplaces & brand websites
Amazon, iHerb and direct brand reviews
Social & community
Reddit, X, Instagram and TikTok
Video & creators
YouTube and creator perspectives

Coverage varies by product and brand.

133 product and brand ratings and mentions across 1 sources.

Good to know

A few useful answers.

Research & further reading

More category questions

How should I store this supplement?

Store in a cool, dry place away from direct sunlight. Most supplements are stable at room temperature (59-77°F). Keep the bottle sealed between uses. Check the label for any specific storage requirements — some probiotics and oils require refrigeration.

Can I take this with other supplements?

Most supplements can be taken together safely. However, some minerals compete for absorption (zinc and iron, calcium and magnesium) and should be taken at different times of day. If you're taking prescription medications, consult your healthcare provider about potential interactions.

How long should I take this supplement?

Most supplements benefit from consistent daily use over 2-3 months to achieve full effect. Some (like vitamins and minerals) can be taken indefinitely as part of a daily routine. Others (like specific herbs) may benefit from cycling. Follow the product's recommended protocol or consult a practitioner.

When is the best time to take this?

Fat-soluble supplements (vitamins A, D, E, K, omega-3, CoQ10) should be taken with a meal containing fat. Water-soluble supplements (B vitamins, vitamin C) can be taken anytime. Minerals are generally best absorbed with food. Probiotics should be taken with or just before a meal. Check the product label for specific timing recommendations.

How do I know if this supplement is working?

Track your specific health goals — energy levels, sleep quality, joint comfort, digestion, mood, etc. Most supplements take 2-8 weeks for noticeable effects. For objective measurement, baseline lab tests before starting (and repeat at 3 months) provide definitive evidence. The Gabriel Score incorporates clinical evidence for expected outcomes.

Supplement information is provided for education and is not a substitute for personalized medical advice. Supplements are not intended to diagnose, treat, cure or prevent disease. Read the current product label before use.

Endurance Products - Endur-C  SR 500mg, 90 Tablets Endurance Products

Apotheca quality score

76/100

The overall score combines several sources of information. The individual dimensions below show where those signals are stronger or more limited; they are not a simple average of the overall score.

Manufacturing5757
Lab verification6565
Review consensus100100
Practitioner signals5050
Community signals6363
Transparency5858
See available brand signals
✓
Good manufacturing practices verifiedStandard
✓
Quality ingredients with verified sourcingGood
✓
Clean FDA regulatory recordNo issues
✓
Positive consumer reviews and community feedbackGood
✓
Authorized distribution channel verifiedDirect

Our score is an editorial assessment, not a product certification or a guarantee of results.

How our scoring works ↗