Forms of silicon in supplements: how OAOSA, ch‑OSA, SiO₂ and MMST differ

Scientific reviewer of the Ukrainian source: Andrii Mokiienko, Doctor of Medical Sciences

Several silicon supplements sit side by side on a pharmacy shelf, yet some cost several times more than others. Every label says “silicon”. How do you tell them apart and understand what you are paying for?

There is a real difference. The same word, “silicon”, covers different chemical forms. They dissolve and are absorbed differently. A higher price alone does not guarantee a better form. Look for two things on the label: the name of the form and the amount of silicon itself, or elemental silicon. Also check whether the brand explains which absorption data it relies on.

The essentials in 30 seconds

What matters more than a large number on the pack? The form of silicon. It is absorbed mainly as soluble orthosilicic acid (OSA) [1]. Poorly soluble forms, silicon dioxide (SiO₂) and silicates, are absorbed much less readily [2].

Why is the acid stabilised? Orthosilicic acid is unstable in concentrated form. It is stabilised so that it stays in a form the body can absorb when used in a supplement [3].

What is OAOSA? OAOSA is stabilised silicic acid in an acacia gum matrix, used in SILINEXT products. Silicic acid is a general term for compounds of silicon, oxygen and hydrogen; the simplest is orthosilicic acid. It is a powder, so the same form is used in both capsules and sachets. Each product provides 500 mg of OAOSA per daily serving: this is the weight of the raw material, which contains around 15 mg of silicon itself, or elemental silicon. For more detail, see “Daily silicon intake”.

Why silicon matters to the body (orthosilicic acid, OSA)

Silicon is studied in relation to the condition of skin, hair and nails, collagen formation and bone mineralisation [3]. It is found in many tissues in the body, including bones, tendons and the wall of the aorta [1].

In laboratory studies (in vitro), orthosilicic acid increased collagen formation [3]. Stabilised forms of OSA have also been studied in people, with researchers assessing the condition of skin, hair and nails [4, 5].

Silicon is absorbed mainly as OSA [1]. This is why the form matters. We discuss what the studies found in “Silicon and skin, hair and nails: what the research shows”.

Who this article is for

• you are choosing a silicon supplement and do not understand why some cost several times more than others;
• you read the ingredients and want to know exactly what “silicon” means;
• you do not want to pay more just for a large number on the label, but you do not want to compromise on quality either.

What to check before buying

• which form is listed as the source of silicon: silicon dioxide or a silicate, orthosilicic acid or stabilised silicic acid, or MMST (monomethylsilanetriol);
• whether the amount of elemental silicon is stated, rather than just the weight of the extract or raw material;
• which absorption data the brand relies on;
• whether a liquid or colloidal format is being presented as proof of better absorption: water in a bottle does not, by itself, make silicon soluble OSA.

When to consult a doctor

Consult a doctor before taking a supplement if you are pregnant or breastfeeding. The same applies if you have kidney disease or take medication regularly. It also applies to children.

Three groups of silicon forms found in supplements

In simple terms, silicon supplements can be divided into three groups:

1. Mineral forms: silicon dioxide (SiO₂), silicates and colloidal silica, which consists of tiny solid particles of silicon dioxide suspended in a liquid.
2. OSA forms: free orthosilicic acid and its stabilised forms.
3. MMST: a separate form in which silicon is bonded to carbon.

Why does this difference matter? Silicon needs to dissolve before it can be absorbed. SiO₂ and silicates must first release soluble OSA in the digestive system. This only happens partially, so these forms are absorbed less readily [2].

Mineral forms: SiO₂ and silicates

Silicon dioxide (SiO₂) is often obtained from bamboo, horsetail or mineral raw materials. That origin may look appealing on a label, but it tells you little about absorption on its own.

For the body to absorb silicon from SiO₂, it must first dissolve, and this only happens partially. In a comparative study, around 1% of the silicon from colloidal SiO₂ was absorbed, and around 4% from magnesium trisilicate (a mineral compound used in antacids). From an OSA solution, the figure was 43% [2].

Why mineral forms remain popular

The reason is simple. SiO₂ is inexpensive, stable and convenient to use in manufacturing. A large number of milligrams on the label can also look more convincing than a small serving of a soluble form.

This does not mean that SiO₂ supplements are bad. But a large number still tells you little about absorption. Two things matter: the form of silicon and how much is in the daily serving [1, 2].

Bioavailability describes the proportion of silicon that becomes available to the body. It is an important criterion when choosing a form [1, 2]. Changes in the condition of skin, hair or bones are assessed separately, in clinical studies [4, 5, 6].

Stabilised OSA forms

Orthosilicic acid (OSA, H₄SiO₄) is a soluble form of silicon that can be absorbed in the digestive system. In a comparative study, soluble OSA was absorbed much more readily than colloidal SiO₂ and magnesium trisilicate [2].

But OSA is unstable in a concentrated solution. Over time, its molecules can join together to form larger, less soluble structures. Silicon in this form is absorbed less readily, which is why the acid is stabilised [3].

Different stabilisers can be used. The stabiliser determines the supplement’s format and may affect absorption.

Which stabilised forms of silicon and MMST are found in supplements?

We discuss what is known about OAOSA absorption in “Malto-OSA or OAOSA”.

Have stabilised forms of silicon been studied clinically?

Yes, some have been studied in people. Researchers assessed not only absorption, but also the condition of skin, hair and nails.

Some of the best-known studies are:

• Ferreira 2018: Malto-OSA and MMST, the condition of skin, hair and nails over 150 days [6];
• Barel 2005: ch-OSA, the condition of skin, hair and nails after 20 weeks of supplementation [4];
• Wickett 2007: ch-OSA, the strength and structure of fine hair over 9 months [5].

We explain what these studies measured and what they found in “Silicon and skin, hair and nails: what the research shows”. Findings on bone tissue are discussed in “Silicon and bones: what the research shows”.

Liquid silicon or powder: what the studies show

The Boqué pilot study compared two liquid OSA forms with a powdered, maltodextrin-based OSA form. Relative absorption was estimated from the increase in urinary silicon over 6 hours: 32.4% and 34.6% for the liquid forms and 27.2% for the powder. The authors concluded that relative absorption was comparable across all three forms [7].

MMST was examined in a different study. Around 64% of the silicon from MMST was absorbed, compared with 43% from an OSA solution. Only 1–4% was absorbed from colloidal SiO₂ and magnesium trisilicate [2], even though both were also given in liquid form in that study.

At first glance, 64% makes MMST look like the clear leader. High bioavailability is indeed one of this form’s strengths. But we cannot say that MMST is twice as good as powdered OSA with its 27.2%. These figures come from different studies, under different conditions, and do not tell us about clinical outcomes.

The conclusion is straightforward. Soluble forms are absorbed more readily than mineral forms. But “liquid silicon” on the label does not, by itself, mean higher bioavailability [2, 7].

Malto-OSA or OAOSA: what is the difference?

Both forms are powders. Both are made by the same manufacturer, the Spanish company Silicium España Laboratorios (the LIVING SILICA® brand). According to the manufacturer, the acid is the same in both forms; the difference is the carrier: maltodextrin or acacia gum. In OAOSA, the acid is microencapsulated in an acacia gum matrix [10].

The maltodextrin-based OSA powder had an estimated relative absorption of 27.2% in the Boqué study, based on urinary silicon measurements. The authors considered this comparable to the two liquid forms [7]. The manufacturer also relies on these data for OAOSA.

How to choose a silicon supplement

The key things to look for on the label are the form of silicon and the amount.

Without further explanation, “silicon 200 mg” may refer to the weight of an extract or the whole complex, rather than elemental silicon.

Silicon from bamboo, horsetail, nettle or diatomite does not, by itself, guarantee better absorption. Look for the exact name of the form [1, 2].

SILINEXT PRO COLLAGEN ACTIVATOR comes in capsules containing OAOSA stabilised silicic acid and vitamin C. The formula is vegan. SILINEXT PRO COLLAGEN MATRIX comes in sachets containing the same OAOSA, collagen peptides from fish, zinc and vitamin C. Of the two products, only MATRIX contains collagen peptides. Both provide the same amount of silicon per daily serving. We start with the form: we explain why we chose OAOSA in “Bioavailable silicon”.

If you already take collagen, you can take ACTIVATOR alongside it. If you want collagen peptides, silicon, zinc and vitamin C in one sachet, choose MATRIX.

Vitamin C contributes to normal collagen formation for the normal function of skin. Zinc contributes to the maintenance of normal skin, hair and nails.

A varied, balanced diet and a healthy lifestyle are important for health. Daily servings for adults: ACTIVATOR, 2 capsules with food; MATRIX, 1 sachet in a glass of water (at least 200 ml). Do not exceed the recommended daily serving. If you take MATRIX, include zinc from other supplements and food when considering your total intake. Each sachet contains 10 mg of zinc. According to the European assessment, the upper limit for adults is 25 mg per day from all sources [11].

The collagen in MATRIX comes from fish, so this product is not suitable for people with a fish allergy. For more help choosing, see “ACTIVATOR or MATRIX: which should you choose?”.

Frequently asked questions

Is silicon from bamboo absorbed? It can be, but it depends on the form. If the silicon in the raw material is mainly SiO₂, only a small proportion dissolves. In a comparative study, silicon from an OSA solution was absorbed tens of times more readily than silicon from colloidal SiO₂ [2]. Bamboo extracts were not studied. So “silicon from bamboo” describes the origin of the raw material, not its bioavailability.

What is “organic silicon”? The term is often used for different forms of silicon, rather than a precise chemical name. Chemists use “organosilicon” for compounds in which silicon is bonded directly to carbon. Of the forms discussed here, only MMST fits that description. In stabilised forms of silicic acid, the organic substance is the stabiliser, such as maltodextrin, vanillin, choline or acacia gum. So look at the name of the form in the ingredients, rather than the word “organic” [1, 2].

Why does ACTIVATOR come in capsules? OAOSA is a powder, and capsules allow the serving to be measured precisely. What matters for absorption is the form of silicon inside, rather than whether the product is liquid or dry [2]. The daily serving of ACTIVATOR for adults is 2 capsules. MATRIX contains the same amount of OAOSA, but in a sachet alongside other ingredients.

Can you get silicon from mineral water? Yes. Mineral waters contain dissolved silicon, but the amount varies greatly between waters. You will see metasilicic acid (H₂SiO₃) on mineral water labels. Here, metasilicic acid is the basis used to express the dissolved silicon content on the label. In Ukraine, silicon in water is expressed in this way [12]. The metasilicic acid figure on the bottle is almost three times the amount of silicon itself in the water. So it should not be compared directly with the milligrams of silicon in a supplement.

Does a larger serving of silicon give better results? A double serving does not mean the body will retain twice as much silicon. A higher dose may increase the amount absorbed, but a substantial proportion is excreted in urine fairly quickly [2, 13, 14]. Follow the daily serving on the label and do not exceed it.

Authorship and scientific review

Author: BIOMOLECULA™ scientific editorial team (based on peer-reviewed scientific sources). Scientific reviewer of the Ukrainian source: Andrii Viktorovych Mokiienko, Doctor of Medical Sciences, Senior Researcher, Associate Professor in the Department of Public Health and Physical Education at the National University of Ostroh Academy; author of the monograph “Кремний в воде. Гигиенические и медико-биологические аспекты” (2020) and co-author of the monograph “Кремній у воді: гігієнічні та медико-біологічні аспекти” (2026). Both titles translate as Silicon in Water: Hygienic and Biomedical Aspects. Review date: 21 August 2026. Publication date: 1 September 2026. Updated: 27 October 2026. Last scientific review: 21 August 2026. These dates refer to the Ukrainian source article.

References

1. Martin KR. The chemistry of silica and its potential health benefits. Journal of Nutrition, Health and Aging. 2007;11(2):94–97. PMID 17435951. (review)
2. Sripanyakorn S, Jugdaohsingh R, Dissayabutr W, Anderson SHC, Thompson RPH, Powell JJ. The comparative absorption of silicon from different foods and food supplements. British Journal of Nutrition. 2009;102(6):825–834. doi:10.1017/S0007114509311757. PMID 19356271.
3. Jurkić LM, Cepanec I, Pavelić SK, Pavelić K. Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: new perspectives for therapy. Nutrition & Metabolism. 2013;10(1):2. doi:10.1186/1743-7075-10-2. PMID 23298332. (review)
4. Barel A, Calomme M, Timchenko A, De Paepe K, Demeester N, Rogiers V, Clarys P, Vanden Berghe D. Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin. Archives of Dermatological Research. 2005;297(4):147–153. doi:10.1007/s00403-005-0584-6. PMID 16205932.
5. Wickett RR, Kossmann E, Barel A, Demeester N, Clarys P, Vanden Berghe D, Calomme M. Effect of oral intake of choline-stabilized orthosilicic acid on hair tensile strength and morphology in women with fine hair. Archives of Dermatological Research. 2007;299(10):499–505. doi:10.1007/s00403-007-0796-z. PMID 17960402.
6. Ferreira AO, Freire ÉS, Polonini HC, et al. Anti-Aging Effects of Monomethylsilanetriol and Maltodextrin-Stabilized Orthosilicic Acid on Nails, Skin and Hair. Cosmetics. 2018;5(3):41. doi:10.3390/cosmetics5030041.
7. Boqué N, Valls RM, Pedret A, Puiggrós F, Arola L, Solà R. Relative absorption of silicon from different formulations of dietary supplements: a pilot randomized, double-blind, crossover post-prandial study. Scientific Reports. 2021;11(1):16479. doi:10.1038/s41598-021-95220-2. PMID 34389753.
8. Marcowycz A, Housez B, Maudet C, Cazaubiel M, Rinaldi G, Croizet K. Digestive absorption of silicon, supplemented as orthosilicic acid-vanillin complex. Molecular Nutrition & Food Research. 2015;59(8):1584–1589. doi:10.1002/mnfr.201400881. PMID 25820464.
9. Tedesco E, Benetti F, Pezzani R. In vitro evaluation of different organic matrices used to modulate silicon bioavailability. FASEB Journal. 2020;34(9):12229–12238. doi:10.1096/fj.202000060RR. PMID 32681588. (in vitro data)
10. US 11,311,621 B2 (US patent holder – Silicium Laboratories, LLC). Organosilicon compound microparticles and process for their preparation. Silicium España Laboratorios, S.L.; EP 3 761 808 B1. Priority: EP18382138.8, 06.03.2018.
11. Scientific Committee on Food. Opinion of the Scientific Committee on Food on the Tolerable Upper Intake Level of Zinc. SCF/CS/NUT/UPPLEV/62 Final, 19.03.2003. https://food.ec.europa.eu/system/files/2020-12/sci-com_scf_out177_en.pdf
12. Бабієнко В.В., Мокієнко А.В., Дубовик С.Л., Рожнова А.М. Кремній у воді: гігієнічні та медико-біологічні аспекти [Silicon in Water: Hygienic and Biomedical Aspects; English title translation]: монографія. Одеса: Прес-кур’єр; 2026. 184 с. ISBN 978-617-7797-65-3.
13. Reffitt DM, Jugdaohsingh R, Thompson RPH, Powell JJ. Silicic acid: its gastrointestinal uptake and urinary excretion in man and effects on aluminium excretion. Journal of Inorganic Biochemistry. 1999;76(2):141–147. doi:10.1016/S0162-0134(99)00126-9. PMID 10612067.
14. Pruksa S, Siripinyanond A, Powell JJ, Jugdaohsingh R. Silicon balance in human volunteers; a pilot study to establish the variance in silicon excretion versus intake. Nutrition & Metabolism. 2014;11(1):4. doi:10.1186/1743-7075-11-4. PMID 24405738.

Disclaimer

This article is for educational and informational purposes only. A food supplement is not a medicinal product and is not intended to diagnose, treat or prevent disease. The collagen in SILINEXT PRO COLLAGEN MATRIX comes from fish, so this product is not suitable for people with a fish allergy. Consult a doctor before use.