Doctor's Best Fully Active B12
vs
Metagenics SeroSyn
Supplement Comparison

  • Vitamin B12 (Cobalamin): Doctor's Best Fully Active B12 has 6.0× more
  • The image below shows:
    • Side-by-side charts with label nutrient amounts, per serving
    • Nutrient forms as listed on the label
    • 11 nutrients compared
Bar chart: per-serving label amounts and listed forms for Doctor's Best Fully Active B12 vs Metagenics SeroSyn.

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Frequently asked questions

Which active ingredients does Doctor's Best Fully Active B12 have?

  • Vitamin B12 (Cobalamin) appears as Methylcobalamin

Which active ingredients does Metagenics SeroSyn have?

  • Vitamin B6 (Pyridoxine) appears as Pyridoxine HCl
  • Vitamin B9 (Folate) appears as Calcium-L-5-methyltetrahydrofolate
  • Vitamin B12 (Cobalamin) appears as Methylcobalamin
  • 5-Hydroxytryptophan
  • Asian Ginseng Extract appears as Asian Ginseng (Panax ginseng) Root Extract standardized to 8% ginsenosides
  • L-Theanine
  • Chinese Skullcap (Scutellaria baicalensis) appears as Chinese Skullcap (Scutellaria baicalensis) Root Extract standardized to 30% flavones

Which categories do Doctor's Best Fully Active B12 and Metagenics SeroSyn belong to?

  • Single Vitamin
  • Single Mineral

What health concerns do Doctor's Best Fully Active B12 and Metagenics SeroSyn address?

  • Brain, Focus & Cognitive Function
  • Energy & Metabolism
  • Neurological Support
  • Mood Support
  • Stress Management

Which product has a higher amount of Vitamin B12 (Cobalamin) per serving?

  • Doctor's Best Fully Active B12 has the highest total amount of Vitamin B12 (Cobalamin): 1500 mcg per serving

How do the serving sizes compare between the two supplements?

  • Serving size:
    • Doctor's Best Fully Active B12: 1 capsule
    • Metagenics SeroSyn: 1 capsule
  • Vitamin B12 (Cobalamin)
    • This supplement has 1500 mcg
    • Recommended Dietary Allowance in men: 2.4 mcg
    • Recommended Dietary Allowance in women: 2.4 mcg
    • Tolerable Upper Intake Level: Not established
  • Vitamin B6 (Pyridoxine)
    • This supplement has 10 mg
    • Recommended Dietary Allowance in men: 1.3 mg
    • Recommended Dietary Allowance in women: 1.3 mg
    • Tolerable Upper Intake Level: 100 mg
  • Vitamin B9 (Folate)
    • This supplement has 555 mcg DFE
    • Recommended Dietary Allowance in men: 400 mcg DFE
    • Recommended Dietary Allowance in women: 400 mcg DFE
    • Tolerable Upper Intake Level: 1000 mcg DFE
  • Vitamin B12 (Cobalamin)
    • This supplement has 250 mcg
    • Recommended Dietary Allowance in men: 2.4 mcg
    • Recommended Dietary Allowance in women: 2.4 mcg
    • Tolerable Upper Intake Level: Not established

Last updated: February 3, 2026

  • Sources & Methodology: Nutrient data and forms are taken directly from Supplement Facts labels. Reviewed and standardized by the VIOscan Research Team. Learn more on the Methodology page.
  • We show the Recommended Dietary Allowance (RDA) when available. If no RDA exists, we show the Adequate Intake (AI). Tolerable Upper Intake Levels (UL) are used for upper limits. Unless otherwise noted, RDAs shown correspond to healthy adults aged 19–50 years and are sex-specific. Separate values exist for 51–70 years and >70 years, and pregnancy and lactation are excluded. All values come from the Dietary Reference Intakes (DRIs) published by the National Academies of Sciences, Engineering, and Medicine (NASEM), Food and Nutrition Board (FNB).
  • Transparency: We’re funded by our users. We don’t have sponsors or affiliate links, and we don’t sell supplements.
  • Editorial standards: we provide independent, impartial and objective data analysis.
  • This analysis is for educational purposes only. It is not a substitute for medical advice.
  • Questions? Read our Frequently Asked Questions or contact us, we’re here to help.
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  • Author: VIOscan Research Team