H2Glow Tropical Punch stick pack leaning against a glass of pink drink on a kitchen counter, beside a supplement bottle, avocado and walnuts

Supplements for dry skin: what actually works

What supplements help dry skin?

Four have controlled trials that measured skin directly: oral hyaluronic acid, collagen peptides, ceramides, and omega fatty acid oils such as flaxseed and evening primrose. Vitamins C and D have indirect evidence only. Hyaluronic acid and collagen have the most trial data. All took 4 to 12 weeks to show a difference, and none replaces a moisturizer.

Part of the winter skin guide. Start here: Why is my skin so dry in winter?

Five things worth knowing

"Tested on skin" is the bar. Many supplements are sold for skin. Far fewer have a placebo-controlled trial that measured hydration or water loss.
The effects are modest. The trials report measurable changes, not transformations.
Everything takes weeks. The shortest trial here ran four.
Vitamins C and D have weaker skin evidence than their reputation.
Supplements add to a winter routine. Cream, shorter showers and a less dry room still do the first-line work.

The evidence, side by side

Supplement	What trials measured	How much evidence	Trial doses
Hyaluronic acid	Higher skin water content, lower water loss, better elasticity	Two placebo-controlled trials cited here: 40 adults and 150 adults	120 mg a day, 12 weeks (the larger trial also tested 60 mg)
Collagen peptides	Better skin hydration and elasticity	Largest body of evidence: a meta-analysis of 26 trials and 1,721 people	Varied by trial
Ceramides	Lower water loss; higher hydration in some	Four small trials, 17 to 51 people, one with no placebo	1.8–2 mg active, or 40–350 mg extract, 4–12 weeks
Flaxseed, borage, evening primrose oil	Lower water loss, less roughness and scaling	Two small controlled trials	About 2 to 3 g of oil a day, 12 weeks
Krill oil (omega-3)	Lower water loss, higher hydration and elasticity	Two pilot trials, about 50 people each	1 or 2 g a day, 12 weeks
Vitamin C	People who eat more have less age-related dryness	One large diet survey; no supplement trial for dry skin cited here	—
Vitamin D	Low blood levels go with drier skin	One study of 83 people; the treatment tested was a cream, not a pill	—
Extra water	Slightly higher skin hydration, mostly in low drinkers	A systematic review of six studies, rated weak	About 2 L a day extra

Illustration of skin layers: surface cells on top, a water-holding gel layer, woven collagen fibres and a small blood vessel feeding from below — *Illustration, not to scale.*

Hyaluronic acid

Hyaluronic acid holds water in the skin. Taken by mouth at 120 mg a day for 12 weeks, it improved the water content of the outer skin layer, water loss and elasticity against placebo in a trial of 40 adults. A larger trial of 150 adults tested 60 mg and 120 mg and found the same pattern, stronger at the higher dose.

Full detail: Does oral hyaluronic acid actually work?

Collagen peptides

Collagen has the most data of anything on this list. A 2023 meta-analysis pooled 26 randomized trials with 1,721 participants and found hydrolyzed collagen improved skin hydration and elasticity against placebo. An earlier one, of 19 trials and 1,125 people, reached the same conclusion and found results by 90 days.

Two cautions. The 2023 authors flagged biases in the included trials and called for larger ones. And these trials used hydrolyzed collagen peptides, which is a specific ingredient.

Why H2Glow uses collagen's amino acids instead of collagen peptides. H2Glow delivers 1,500 mg of glycine, proline and lysine, the amino acids collagen is built from. We chose this route for oral efficacy and whole-body use. Glycine, proline and hydroxyproline make up 57% of the amino acids in collagen, and one analysis estimated that the glycine the body makes, plus a typical diet, may fall about 10 g a day short of what the body's metabolism needs, collagen synthesis included. Supplying those building blocks directly gives every tissue that makes collagen, skin included, the raw material, in a form the body absorbs as is. The skin trials above tested peptides; H2Glow's amino-acid route rests on this biochemistry rather than on skin trials of its own.

Ceramides

Ceramides are the lipids that seal water into the skin, and the skin's own supply falls in winter. Three of four small trials of oral ceramides found lower water loss through the skin after 4 to 12 weeks; the fourth measured hydration instead. One of them was run in winter. The evidence is early.

Full detail: Do ceramide supplements work?

Omega oils: flaxseed, borage, evening primrose, krill

Several small trials tested plant and marine oils taken by mouth for 12 weeks.

Flaxseed and borage oil. In women taking about 2.2 g of fatty acids a day, water loss fell by about 10% at six weeks, and roughness and scaling decreased. Those measures did not change in the placebo group. Skin hydration rose in the oil groups, but it rose in the placebo group too, so that result is not clean.
Evening primrose oil. At 3 g a day, skin moisture, water loss, firmness and roughness were all significantly better than placebo at week 12, and not yet at week 4.
Krill oil. Two pilot trials, 51 and 50 adults, found 1 g and 2 g a day lowered water loss and raised hydration against placebo. The authors work for the krill-oil company.

These are a different category from the first three: fats the skin uses to build its barrier, taken in gram amounts.

Vitamin C and vitamin E

Is vitamin C good for dry skin in winter? The evidence is indirect. In a survey of 4,025 American women aged 40 to 74, those with higher vitamin C intake from food were less likely to have age-related skin dryness. Higher intake of linoleic acid, a fat found in seeds and nuts, showed a stronger link. That is diet and association, not a supplement trial.

What about vitamin E? We did not find a trial that tested a vitamin E supplement for dry skin. It is widely used in creams, which is a different question from taking it by mouth.

Most "vitamin C for dry skin" searches are about serums. That is a topical question and a different page.

Vitamin D

Winter means less sun and, for many people, lower vitamin D. In a study of 83 people, those with lower vitamin D levels in their blood had lower skin moisture. The same study then tested vitamin D as a cream on dry legs, and it helped. It did not test a vitamin D pill for dry skin. So the link is real and the supplement question is open.

Electrolytes and water

Does drinking more water help? A little. A systematic review of six studies found a slight rise in skin hydration with extra water, mainly in people who drank little, and rated the evidence weak.

Can low electrolytes cause dry skin? Electrolytes control where water goes in the body, which is the reasoning behind electrolyte drinks for skin. We did not find a published trial that tested an electrolyte drink against placebo for dry skin. It is a reasonable mechanism without direct proof yet.

More: Electrolytes for skin: do they help? and Why water isn't enough.

How to choose

Start with the two that work on water directly: hyaluronic acid to hold it, ceramides to keep it in.
Add a collagen source or an omega oil if you want the next layer. For collagen, that means peptides or collagen's amino acids, the route H2Glow uses. Omega oils are separate products with gram-level doses.
Check vitamin D with your doctor if you get little winter sun. That is worth knowing for reasons beyond skin.
Give anything 8 to 12 weeks before judging it.
Keep the outside routine. See Why is my skin so dry in winter? and Does indoor heating dry out your skin?.

Where H2Glow fits

One stick a day covers the first group and part of the rest:

In H2Glow	Amount	Compared with the trials above
Sodium hyaluronate	250 mg	Trials used 120 mg
Rice phytoceramides	40 mg	Same source and amount as the rice study, which had no placebo group
Vitamin C	100 mg	No supplement trial for dry skin cited
Sodium, potassium, magnesium	300 / 200 / 150 mg	No electrolyte trial for dry skin found
Glycine, proline, lysine	1,500 mg	Collagen's amino-acid building blocks, chosen over peptides for oral efficacy and whole-body use (see "Why H2Glow uses collagen's amino acids" above). The skin trials tested peptides

Not in H2Glow: omega oils and vitamin D; for collagen, H2Glow uses the amino-acid route instead of peptides, for the reasons above. Omega oils and vitamin D are separate products and can be taken alongside it.

Fill and seal: hyaluronic acid helps skin hold water; ceramides help reduce water loss; H2Glow contains both — *Ingredient-level evidence; not a trial of H2Glow.*

What supplements do not do

They do not replace moisturizer in winter.
They do not work in days.
They do not treat eczema, winter itch or a rash. See a dermatologist for those.

Make it a Step 0 routine

Air. Add moisture back to heated rooms.
Outside. Moisturize to slow water loss from the surface.
Inside. Drink water with electrolytes, and look at ingredients with human skin trials, such as hyaluronic acid and ceramides.
Daily. Keep it up through the heating season, not only when skin feels tight. That daily inside layer is Step 0.

Using a sauna, red light mask or PEMF mat this winter? The Glow Protocol applies the same idea to beauty-tech.

Frequently asked questions

What supplements help dry skin in winter?

Oral hyaluronic acid, collagen peptides, ceramides and omega oils such as flaxseed or evening primrose each have controlled trials measuring skin hydration or water loss. Effects were modest and took 4 to 12 weeks.

What vitamins are good for dry skin in winter?

Vitamin C intake from food is linked to less age-related skin dryness, and low vitamin D levels go with drier skin. Neither has a strong supplement trial for dry skin specifically.

Is vitamin C good for dry skin?

People who eat more vitamin C have less age-related dryness in survey data. That is an association from diet, not proof that a vitamin C supplement fixes dry skin.

Does vitamin D help dry skin?

People with lower vitamin D levels had lower skin moisture in one study. That study tested vitamin D as a cream, not a pill, so whether a supplement helps is not established.

Do skin hydration supplements work?

Some do, modestly. Hyaluronic acid and collagen peptides have the most trial evidence for raising skin hydration. Ceramides and omega oils have smaller trials showing lower water loss.

Do electrolytes help dry skin?

Electrolytes govern where water goes in the body. We did not find a placebo-controlled trial of an electrolyte drink for dry skin, so the benefit is plausible and not yet proven.

How long do supplements take to work on dry skin?

Four to twelve weeks in the trials. Evening primrose oil showed no difference at week 4 and a clear one at week 12.

Can I take hyaluronic acid, ceramides and collagen together?

None of the trials cited here reported a problem with any of them, and they act in different ways. Ask your doctor if you are pregnant, nursing or on medication.