Vitamin C

Expert Positions

Andrew Huberman

Limited Effectiveness for Colds

Peter Attia

Skeptical of Mega-Dosing

Rhonda Patrick

Recommends for Immune & Cardiovascular Health

Bryan Johnson

Includes in Daily Protocol

Mark Hyman

Recommends Broadly for Immune & Stress Support

The Verdict

3 of 5 experts view vitamin C as broadly useful — Patrick has a dedicated deep-dive covering oral vs. IV forms, Hyman recommends it across dozens of videos for immune support, stress, and detox, and Johnson includes it in his daily protocol alongside iron. Huberman notes that high-dose vitamin C has shown limited effectiveness for colds. Attia is the most skeptical, arguing that mega-dosing offers no benefit beyond correcting deficiency and that oral absorption is severely limited.