Vitamin C

Also called ascorbic acid

What Huberman said

Huberman says there is some evidence, 'and it's not great, frankly', that six to eight grams of vitamin C a day can perhaps delay the onset of a cold or shorten its duration. He calls these very high doses with not a very robust effect. He adds that a 2023 meta-analysis showing a benefit was retracted, that high doses do not seem effective for treating or preventing colds and flu, and that vitamin C is probably not a very good investment if you take it only for immune function.

Doses, as he worded them

“six to eight grams, grams, so that's 6,000 to 8,000 milligrams of vitamin C per day”[1]
doses in the evidence he describes (not a recommendation)

Quoted, not prescribed. Talk to a doctor or pharmacist first if you take medication, are pregnant or have a health condition.

Cautions he mentions

For most people not accustomed to much vitamin C, six to eight grams will likely cause significant gastric distress.[1]
The evidence is 'not great, frankly'; it is 'not a very robust effect'.[1]

Safety notes from independent sources

The US upper limit for vitamin C is 2,000 mg a day for adults, so 6 to 8 g a day is three to four times that. High intakes could contribute to kidney stones, especially in people with kidney disorders, although it is not clear that vitamin C plays a role. NIH ODS: Vitamin C
The NHS says more than 1,000 mg of vitamin C a day can cause stomach pain, diarrhoea and flatulence. NHS: Vitamin C

Where he said it

1
“There is some evidence, and it's not great, frankly, that points to the fact that taking six to eight grams,”
How to Prevent & Treat Colds & Flu
Episode · 01:42:20 · 2024
Watch from 01:42:20 Episode page

This page reports what Andrew Huberman has said. It isn’t medical advice and NSDR.co isn’t affiliated with Huberman Lab. Talk to a doctor or pharmacist first if you take medication, are pregnant or have a health condition. Safety information