Liposomal Vitamin C vs Standard Vitamin C — What the Studies Show

TL;DR. Above ~200 mg per dose, the gut’s vitamin C transporters saturate and additional standard ascorbic acid is largely excreted. Liposomal vitamin C bypasses that saturation by entering through the lipid pathway. Studies show roughly 2× higher plasma vitamin C from liposomal vs equivalent doses of plain ascorbic acid. For routine daily supplementation under 500 mg, standard works fine. For higher therapeutic doses, liposomal is the better-value choice.

The saturation problem

The intestine absorbs vitamin C through two sodium-dependent transporters (SVCT1 and SVCT2). They’re efficient but limited. As dose increases past ~200 mg per single intake, the transporters saturate and the excess vitamin C is not absorbed — it passes through the small intestine into the colon, where it draws water (causing loose stools) and is largely excreted unchanged.

This is why taking 5 g of vitamin C in one dose produces only marginally higher plasma levels than taking 500 mg — and almost certainly causes diarrhoea.

How liposomal bypasses it

Liposomal vitamin C is ascorbic acid encapsulated inside a microscopic phospholipid bilayer that mimics human cell membranes. The gut wall absorbs the liposome through the lipid pathway — the same route used for dietary fats — not through the SVCT transporters. The transporters don’t saturate because they’re not involved.

What the studies show

Davis JL et al. (Nutrition and Metabolic Insights, 2016) compared 4 g of liposomal vitamin C against 4 g of plain ascorbic acid in a randomised crossover study. Liposomal peak plasma concentration was significantly higher and the AUC (area under the curve) was nearly double.

Łukawski et al. (Journal of Liposome Research, 2020) confirmed the bioavailability advantage in a separate trial, with the additional finding that liposomal vitamin C reached higher intracellular leukocyte concentrations — the form most relevant to immune function.

When standard is fine, when liposomal is better

• Routine daily 100–500 mg: standard ascorbic acid is fine and much cheaper.
• Higher therapeutic doses (1,000–3,000 mg): liposomal absorbs more efficiently and causes much less GI upset.
• Acute illness recovery: liposomal lets you reach higher plasma levels without the diarrhoea ceiling.
• People with sensitive guts: liposomal is dramatically gentler.

See our liposomal technology pillar page for the underlying science, and the products page for our liposomal vitamin C range.