Orthosilicic Acid Hair Studies Worked, But Absorption Varies 10-Fold

The Oasis Health Journal · Submitted September 24, 2026 · 10:02 AM EDT

By Marlo Quist · Edited by Priya Raman, C.N.C.

Orthosilicic acid is a water-soluble form of silicon that has been shown in studies to improve hair thickness and reduce nail brittleness.

Silicon is the third most abundant trace element in the human body, after iron and zinc.

The body does not synthesize it. You get it from food or you do not get it. That is where supplements come in. And that is where the problem starts, because the absorption rate for silicon supplements varies by roughly ten-fold depending on which chemical form you bought.

Ten-fold is the difference between a thing that works and a thing that does not.

What the Studies Actually Measured

A 2025 review in Skin Appendage Disorders evaluated supplements for nail health and noted that choline-stabilized orthosilicic acid has been shown to improve the clinical appearance of nails, including strength and brittleness.

The review also noted that manufacturers are not required to carry out efficacy and safety studies before marketing dietary supplements.

So they do not.

The same review stated plainly that dermatologists must be aware that recommendations are only as solid as the available evidence. The evidence for orthosilicic acid improving nails exists. The evidence for most other things you can buy does not.

I guess that is the honor system.

A 2016 review published in Anais brasileiros de dermatologia examined silicon for skin and hair care. It suggested that silicon is important for optimal collagen synthesis and activation of hydroxylating enzymes, which improves skin strength and elasticity.

Regarding hair, the review noted that a higher silicon content in hair correlates with a lower rate of hair loss and increased brightness.

That review also stated that silica supplements are widely used, but silicon bioavailability varies from below one percent to close to fifty percent depending on the chemical form.

Below one percent means you are drinking expensive water with a label. The label is doing all the work.

Orthosilicic Acid Hair and Bioavailability

The 2016 review stated that among the different chemical forms available, orthosilicic acid presents the highest bioavailability.

Other forms have absorption inversely proportional to the degree of polymerization.

Polymerization is when small molecules link into chains. The bigger the chain, the less your gut absorbs it. So if you are comparing a bioavailable silica supplement, you want orthosilicic acid or something very close to it.

You do not want a long polymer that your digestive system looks at and then ignores.

That is not hostility. That is chemistry.

The review also noted that clinical studies evaluating safety and efficacy are still lacking. That was published in 2016. It is 2026 now. The phrase 'still lacking' remains accurate.

Silicon Is Present, Not Proven

Silicon is present in water, plants and animals.

On the skin, it is suggested that silicon improves collagen and enzyme activity. In hair, it is suggested that more silicon means less loss and more shine.

Those are suggestions backed by chemical reasoning and a few human trials, not ironclad proof you can take to the bank.

The mechanism makes sense. The studies show improvement. But the studies are small, the supplement forms vary wildly in what actually gets absorbed, and nobody is required to prove their bottle works before they sell it to you.

That is the regulatory landscape for dietary supplements in the United States. You can sell it, and then maybe someone will study it later.

Or not.

What You Are Actually Buying

If the label says orthosilicic acid, ideally stabilized with choline, you are buying the form with the best absorption data.

If it says colloidal silica, silica gel, or some other larger molecule, you are buying something with absorption in the single digits. Possibly below one percent.

The bottle does not tell you the absorption rate. The bottle tells you the serving size.

If fifty percent of the dose absorbs or one percent absorbs, the label looks identical.

You find out later, or you do not find out at all, because hair and nails grow slowly and the difference between something and nothing takes months to notice.

By then you have already bought three bottles.

The 2025 review stated it clearly: dermatologists must specify to patients that recommendations are as solid as the available evidence. The evidence for orthosilicic acid improving nails and potentially supporting hair thickness exists.

The evidence that the thing you bought at the dose on the label will do that does not necessarily exist.

That is not a flaw in orthosilicic acid. That is a flaw in how supplements are sold.

This article is education and reporting on published research. It is not medical advice, and nothing here is intended to diagnose, treat, cure or prevent any disease. Talk to your own clinician about your own situation.

Sources

1. Nail Supplements: When, How, and Why?, Skin appendage disorders (2025).
2. Use of silicon for skin and hair care: an approach of chemical forms available and efficacy, Anais brasileiros de dermatologia (2016).