Liposomal vitamin C: why Lipo C uses three forms
The absorption of ascorbic acid is capped by a saturable transporter. Three chemical forms, three routes: the formulation logic behind Lipo C, the documented mechanisms and the limits of the data.
The short answer: the intestine absorbs vitamin C through a saturable transporter. Past a certain single dose, taking more no longer raises what actually reaches the blood. Lipo C answers that constraint not with quantity but with three chemical forms, each using a different route.
The absorption ceiling
L-ascorbic acid crosses the intestinal wall mainly through SVCT1, an active, sodium-dependent and saturable transporter. Cellular uptake then relies on SVCT2, densely expressed in the brain, adrenal glands and white blood cells. Saturating SVCT1 has a measurable consequence: the absorbed fraction falls as the dose rises.
| Single oral dose | Approximate absorption |
|---|---|
| 200 mg | over 90 % |
| 1 g | around 70 % |
| 3 g | roughly 40 to 50 % |
| over 10 g | 20 to 30 % or less |
Orders of magnitude from Levine et al. (1996) and the review by Lykkesfeldt and Tveden-Nyborg (2019).
Multiplying the dose therefore multiplies mostly what is excreted by the kidneys, and the residual fraction left in the colon — the one behind the digestive discomfort familiar to practitioners. Two strategies exist to work around the limit: bypass the intestine, which is what an intravenous infusion does, or change the molecule and its vehicle, which is what galenics allows. Lipo C belongs to the second.
First answer: the liposomal fraction
A liposome is a spherical vesicle made of one or more phospholipid bilayers, structurally analogous to a cell membrane. Its outer surface rests mainly on phosphatidylcholine; its aqueous core holds dissolved vitamin C.
Several absorption mechanisms are proposed in the literature: partial fusion with intestinal membranes, endocytosis by enterocytes, lymphatic transport, uptake via the M cells of Peyer's patches. Current consensus rules out liposomes passing intact into the circulation. Part is degraded in the gut; a sufficient fraction persists to improve overall bioavailability.
The strongest human data come from the randomised double-blind placebo-controlled trial by Purpura et al. (2024), which reports, compared with a non-encapsulated form, a 27 % increase in plasma Cmax, 21 % in area under the curve and 20 % in peak leukocyte concentration. The scoping review by Carr and colleagues (2025), covering ten studies, concludes that nine show increased bioavailability, with gains ranging from 8 % to over 30 %.
What the liposomal route does not do
Does an oral liposomal formulation reproduce the concentrations of an infusion? The figures settle the question.
| Situation | Plasma concentration |
|---|---|
| Deficiency | under 11 µmol/L |
| Normal status | 50 to 80 µmol/L |
| Physiological saturation | 80 to 100 µmol/L |
| High classic oral dose | 150 to 250 µmol/L |
| Liposomal form | 180 to 320 µmol/L |
| IV infusion, 25 to 50 g | 10 to 20 mmol/L |
The gap is a factor of fifty to a hundred. The pharmacological mechanisms sought in integrative oncology, which rest on extracellular hydrogen peroxide production at very high concentration, remain the exclusive domain of the intravenous route. An oral formulation does not compete with it, and does not claim to.
Ascorbyl palmitate
The liposome carries an intrinsic fragility: its phospholipids oxidise. Lipid peroxidation degrades the bilayer, alters vesicle size and compromises encapsulation, especially in a dry powder exposed to humidity, oxygen and temperature swings. A dry liposomal formulation must therefore protect its own vehicle.
Ascorbyl palmitate is an ester of ascorbic acid and palmitic acid, amphiphilic, whose lipophilic end inserts into fatty phases. The food industry has used it since Cort (1974) to stabilise vegetable oils and emulsions. That is its primary function inside Lipo C: protecting the liposome's phospholipids from peroxidation.
A second contribution deserves precision. Ascorbyl palmitate releases ascorbic acid on digestive hydrolysis, and the work of DeRitter et al. (1951) indicates that this ascorbate shows bioavailability comparable to ascorbic acid given alone. It therefore contributes to the total vitamin C of the formulation.
L-ascorbic acid
L-ascorbic acid remains the physiological reference form, the one nearly all clinical literature rests on. Within minutes of ingestion, the free fraction exposes the intestinal mucosa directly to a high ascorbate concentration and engages SVCT1 without delay. Systemic distribution follows, then tissue uptake via SVCT2.
The logic of complementarity
Each form occupies a distinct physicochemical domain.
| Form | Preferred compartment | Status of the data |
|---|---|---|
| L-ascorbic acid | Intestinal lumen, SVCT1, SVCT2, GLUT absorption | Established |
| Ascorbyl palmitate | Lipid phases of the formulation, ascorbic contribution after hydrolysis | Established in vitro and in food science |
| Liposomal fraction | Plasma and leukocyte bioavailability | Established in humans, ten studies reviewed |
Staggered exposure over time: immediate digestive action from the free fraction, protection of the phospholipids during transit thanks to the palmitate, prolonged diffusion through the liposomal structures. The formulation rests on the convergence of individually documented mechanisms.
This is the same reasoning that governs the choice of active forms elsewhere in our range, whether in the choice of B9 form or in the way we approach interactions between nutrients.
In practice
One capsule of Lipo C provides 491 mg of vitamin C across the three forms. Vitamin C contributes to the reduction of tiredness and fatigue, to the normal function of the immune system and to the protection of cells from oxidative stress. On when to take it, see our note on when to take your vitamins.
Our daily multivitamin, base One, already carries 580 mg of vitamin C per serving. Lipo C is not its replacement: it is a shorter, form-focused intervention.
Sources
- Levine M, et al. Vitamin C pharmacokinetics in healthy volunteers. PNAS. 1996;93(8):3704-3709.
- Lykkesfeldt J, Tveden-Nyborg P. The pharmacokinetics of vitamin C. Nutrients. 2019;11(10):2412.
- Purpura M, et al. Liposomal delivery enhances absorption of vitamin C into plasma and leukocytes. Eur J Nutr. 2024. PMID 39237620.
- Carr AC, et al. Do liposomal vitamin C formulations have improved bioavailability? A scoping review. 2025. PMC12163105.
- Łukawski M, et al. New oral liposomal vitamin C formulation. J Liposome Res. 2020. PMID 31264495.
- Gopi S, Balakrishnan P. Liposomal and non-liposomal ascorbic acid. J Liposome Res. 2021. PMID 32901526.
- Ross D, et al. Ascorbate 6-palmitate protects human erythrocytes from oxidative damage. Free Radic Biol Med. 1999;26:81-89.
- DeRitter E, et al. Physiologic availability of palmitoyl-L-ascorbic acid. Science. 1951;113:628-631.
- Cort WM. Antioxidant activity of ascorbyl palmitate. JAOCS. 1974;51:321-325.
- Linus Pauling Institute, Micronutrient Information Center — Vitamin C: supplemental forms.
This article explains documented mechanisms and states the limits of the current data. It is not medical advice and does not describe any therapeutic effect. A food supplement is no substitute for a varied, balanced diet and a healthy lifestyle.