Back-Flex

product on market Tablet or Pill Foster Regal 🟢 Safety: 96/100
Brand: Foster Regal
🟢 96/100

This product looks safe

  • Manganese: 75mg is 6.8× the Tolerable Upper Intake Level (11mg)
  • 50% of ingredients have research evidence
C Label Compliance Grade

Product Label

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Safety Alerts

⚠️ Manganese: 75mg is 6.8× the Tolerable Upper Intake Level (11mg)

Label Data

1 Tablet(s) Serving Size
90 Servings
Other Combinations Product Type
50% Evidence Coverage

Supplement Facts — Evidence Check

Vitamin C
26 mg (43% DV)
100 IU (25% DV)
✅ Within RDA (0.2× RDA of 0.015 mg) 📚 604 studies (Tier A: 16, B: 251)
RDA 0.015mg This product: 0.0025mg UL 0.1mg
3 mg (150% DV)
✅ 2.3× RDA — within safe limits 📚 113 studies (Tier A: 3, B: 35)
RDA 1.3mg This product: 3mg UL 100mg
Calcium
75 mg (7.5% DV)
40 mg (10% DV)
📊 Market median: 4002.0mg (1 products) 📚 20 studies (Tier A: 0, B: 2)
This product: 40mg
5 mg (33% DV)
✅ Within RDA (0.5× RDA of 11 mg) 📚 258 studies (Tier A: 6, B: 134)
RDA 11mg This product: 5mg UL 40mg
75 mg (3750% DV)
⚠️ Exceeds Tolerable Upper Intake Level by 6.8× (UL: 11 mg) 📚 8 studies — no high-quality reviews
RDA 2.3mg This product: 75mg UL 11mg
Potassium
17 mg (1% DV)
250 mg
📊 Market median: 1000.0mg (1115 products) 📚 22 studies (Tier A: 0, B: 9)
This product: 250mg
MSM
250 mg
📊 Market median: 1000.0mg (2 products)
This product: 250mg

Other Ingredients

Vegetable Cellulose Vegetable Stearic Acid Silica

Label Claims — Verification

❓ Nutrient
❓ All Other
❓ Structure/Function
All Other (99% of products) Structure/Function (83% of products) Nutrient (54% of products)

Target Groups

Adult (18 - 50 Years) Kosher Women (not pregnant or lactating) Gluten Free

Product Information

📋 Directions for Use

Directions: As a dietary supplement, take 1 tablet three times daily.

⚠️ Warnings & Precautions

Tamper evident: Do not use this product if imprinted foil seal under cap is broken or missing.

Caution: Do not take this product if you are pregnant, nursing or allergic to shell fish.

Caution: Do not take this product if you are pregnant, nursing or allergic to shell fish.

Contains crustacean shellfish (crab & shrimp) ingredients.

🧪 Formulation Notes

Mfg. in a Ko Kosher Certified, FDA Registered Facility using Good Manufacturing Practices (GMPs)

Mfg. in a Ko Kosher Certified, FDA Registered Facility using Good Manufacturing Practices (GMPs)

Conforms to USP <2091> for weight. Meets USP <2040> disintegration for maximum bioavailability.

Made in USA

Manganese glucosamine - MSM

Nutritionally supports healthy back function

Gluten free

Additional Information

Keep tightly closed. Store at room temperature: 59 degrees - 86 degrees F (15 degrees to 30 degrees C).

Product Details

UPC / SKU 3 64175 14790 9
DSLD Entry Date 2022-04-11
Product Type Other Combinations
Form Tablet or Pill
Brand Foster Regal
DSLD ID 259936
Data Updated 2026-04-11

Research Evidence

371 Research Sources
54 Avg Quality Score
148 Meta Analysis
82 Systematic Review
71 Rct
62 Clinical Trial
2 Regulatory Source
1 Cochrane Review
1 Narrative Review
1 Other
1 Openfda Safety
A Vitamin C supplementation in pregnancy
Meta Analysis The Cochrane database of systematic reviews 2015
PubMed DOI Cochrane
A Vitamin C supplementation for the primary prevention of cardiovascular disease
Systematic Review The Cochrane database of systematic reviews 2017
PubMed DOI Cochrane
A Vitamin C for preventing and treating the common cold
Meta Analysis The Cochrane database of systematic reviews 2013
PubMed DOI Cochrane
A Vitamin C for preventing and treating pneumonia
Meta Analysis The Cochrane database of systematic reviews 2013
PubMed DOI Cochrane
A Vitamin E supplementation in pregnancy
Meta Analysis The Cochrane database of systematic reviews 2015
PubMed DOI
A Vitamin C supplementation for prevention and treatment of pneumonia
Meta Analysis The Cochrane database of systematic reviews 2020
PubMed DOI Cochrane
A Vitamin C supplementation for prevention and treatment of pneumonia
Systematic Review The Cochrane database of systematic reviews 2021
PubMed DOI Cochrane
A Nutritional interventions for preventing and treating pressure ulcers
Meta Analysis The Cochrane database of systematic reviews 2024
PubMed DOI
A Does Vitamin C Supplementation Provide a Protective Effect in Periodontal Health? A Systematic Review and Meta-Analysis
Meta Analysis International journal of molecular sciences 2024
PubMed DOI
A Circulating vitamin C concentration and risk of cancers: a Mendelian randomization study
Meta Analysis BMC medicine 2021
PubMed DOI
View all evidence for Vitamin C →

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