Bioavailable silicon: what is OAOSA and why does form matter?

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

When hair starts to thin, nails break and skin loses firmness, vitamins or collagen are usually the first things that come to mind.

We are familiar with calcium, magnesium and iron, but silicon tends to come to mind only when we think of sand or electronics. Yet researchers are actively studying its relationship with the body’s own collagen production [1, 2].

How well silicon from a supplement is absorbed depends on its form. One bioavailable form of silicon is orthosilicic acid (OSA), which dissolves and is absorbed in the digestive tract [3]. In a comparative study, only around 1% of the silicon in colloidal silicon dioxide was absorbed [4].

We explain how to read a supplement label, what studies of stabilised forms of silicon have found about skin, hair and nails, and why we chose OAOSA.

The essentials in 30 seconds

Why does “silicon 200 mg” tell you little about absorption? Because silicon absorption depends primarily on its chemical form: some forms are absorbed many times more readily than others [4]. So look for the form of silicon and the amount of elemental silicon on the label, rather than the weight of a plant extract.

What is bioavailable silicon? It is silicon in a soluble form that the body can absorb, including orthosilicic acid (OSA) and its stabilised forms [3, 4]. The mineral form, colloidal silicon dioxide, is absorbed much less readily than soluble forms [4].

How are silicon and vitamin C connected to collagen? Researchers are studying the relationship between silicon and the body’s own collagen production [1, 2]. In a laboratory study (in vitro) using human cells, orthosilicic acid increased collagen synthesis [5]. The effect depended on an enzyme that needs vitamin C to work [5].

What is OAOSA? OAOSA is a powdered form of silicon: stabilised silicic acid in an acacia gum matrix [6]. Silicic acid is a general term for compounds of silicon, oxygen and hydrogen; the simplest is orthosilicic acid. According to the manufacturer’s description, the matrix releases the acid gradually in the intestine.

SILINEXT products at a glance

OAOSA is at the heart of both SILINEXT formulas. The daily serving of each product contains 500 mg of OAOSA, providing around 15 mg of elemental silicon.

SILINEXT PRO COLLAGEN ACTIVATOR comes in capsules containing OAOSA stabilised silicic acid and vitamin C. SILINEXT PRO COLLAGEN MATRIX comes in sachets containing the same OAOSA, collagen peptides from fish, zinc and vitamin C.

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.

The daily serving, directions and precautions are set out in “How much silicon is in a daily serving?”. For help choosing between the two products, see “ACTIVATOR or MATRIX: which should you choose?”.

What “silicon” on a label really means

Supplement labels often carry a simple statement: “silicon 200 mg”. It sounds convincing. The number is large, the trace element is familiar, and the label usually says that the silicon comes from bamboo, horsetail, nettle, oat straw, diatomite or another “natural” raw material. But the number alone does not tell you the most important thing: what form the silicon is in.

Silicon exists in different chemical forms. Some dissolve readily and can enter the bloodstream. Others pass through the digestive tract largely unabsorbed.

In the same 2009 study in which around 1% of the silicon from colloidal silicon dioxide was absorbed, silicon from horsetail dissolved poorly in a digestion model [4]. Liquid supplements also contain silicon in different chemical forms, such as a choline-stabilised form, and these are not all absorbed to the same extent [4]. Whether the silicon comes from plants, diatomite or quartz, or is supplied in a liquid, the rule is the same: look for the name of the form in the ingredients, not just the number of milligrams. For a comparison, see “Forms of silicon in supplements”.

If the form is not specified, “silicon 200 mg” tells you little about how much silicon your body will receive. In the ingredients list, the form may be named “orthosilicic acid”, “stabilised silicic acid” or “silicon dioxide”, for example. Also look for the amount of elemental silicon in the daily serving.

Skin, hair and nails: what the studies found

Stabilised forms of OSA, as well as MMST (a methylated form of silicon), have been studied in people. Researchers assessed skin, hair and nails. All three studies below were randomised and included a control group.

• MMST and a maltodextrin-based form, 10 mg of silicon per day, 150 days, 51 women. Wrinkles and sun-related dark spots decreased from baseline in both silicon groups [7]. Maltodextrin is a food-grade carrier.
• A choline-stabilised form, 10 mg of silicon per day, 20 weeks, 50 women. Women with sun-damaged facial skin (photoageing) had smoother skin than women in the control group. The skin’s mechanical properties also improved. Instrument measurements showed that its elasticity became more uniform. The participants assessed hair and nail brittleness themselves: in the silicon group, hair and nails broke less often at the end of the study than at the start [8].
• A choline-stabilised form, 10 mg of silicon per day, 9 months, 48 women. Women with fine hair in the silicon group retained hair strength better than those in the control group [9]. Hair became thicker compared with baseline in the silicon group, while thickness did not increase in the control group.

These studies are discussed in more detail in our separate article on silicon, skin, hair and nails.

How silicon is connected to the body’s own collagen production

Collagen is the main structural protein in connective tissue. It is found in skin, bones, cartilage, ligaments, tendons, gums and blood vessel walls.

To make strong collagen, the body needs more than amino acids alone. It also needs enzymes and cofactors (supporting substances) to “assemble” the collagen structure correctly.

Collagen is formed through a series of steps. At one of them, an enzyme called prolyl hydroxylase makes the collagen helix strong and stable. This is the step that requires vitamin C.

This is where silicon becomes interesting. In a laboratory study (in vitro), orthosilicic acid at concentrations naturally found in the body increased type I collagen synthesis [5]. The researchers used human cells similar to those that build bone. The effect disappeared when they blocked prolyl hydroxylase, the same enzyme that needs vitamin C [5]. These laboratory observations help us understand which steps in collagen formation silicon may be connected to.

Why orthosilicic acid is stabilised, and what OAOSA is

Orthosilicic acid dissolves readily and is well absorbed. But in concentrated form it is unstable: its molecules join together, and the acid turns into less soluble forms that are absorbed less readily.

To prevent this, the acid is stabilised. There are several ways to do this:

• maltodextrin is a food-grade carrier used to make a powdered form [7, 10];
• vanillin is used to stabilise one of the forms used in supplements [11];
• choline is used in ch-OSA [4, 8];
• collagen was used as the carrier for a form studied in a laboratory experiment (in vitro) [12];
• acacia gum is a dietary fibre with a long history of use in food production; it forms the matrix of OAOSA [6].

All these approaches share the same goal: to keep the acid available for absorption.

OAOSA is stabilised silicic acid microencapsulated in an acacia gum matrix [6]. The manufacturer’s catalogue calls it Acacia Gum-OSA. According to the manufacturer, the matrix releases the acid gradually in the intestine.

In a 2021 pilot study, relative silicon absorption from a powdered, maltodextrin-based form of orthosilicic acid was estimated at 27.2% over 6 hours, using the increase in urinary silicon as the measure [10]. The manufacturer also draws on these absorption data for the acacia gum-based form.

Silicon in the body: where it is found and why it is studied

Silicon occurs naturally in the human body. It is found in collagen-rich connective tissue, including skin, bones and blood vessel walls [13].

Chicks whose diets lacked silicon grew and developed more slowly. The journal Science reported this as far back as 1972 [14]. Later, the large Framingham population study found a positive association between dietary silicon intake and bone mineral density in men and premenopausal women [15].

Silicon is thought to circulate in the blood almost entirely as orthosilicic acid, the same soluble form that is absorbed in the digestive tract [1]. Blood silicon levels decline with age, particularly in women [16].

Where silicon comes from in an everyday diet

In the Framingham study, women consumed an average of around 24–25 mg of silicon per day from food, and men 30–33 mg [17]. These figures describe actual intake. There is no official daily reference intake for silicon in the EU [18]. The main sources for women were bananas and green beans; for men, beer and bananas [17].

But the amount of silicon in a food and the amount absorbed are different things. In a comparative study, around 44% of the silicon in green beans was absorbed, compared with around 4% from bananas [4]. This was a different study from the one that reported 27.2% for the maltodextrin-based powder, so the figures should not be compared directly. For both foods and supplements, the form of silicon matters as well as the amount. Mineral water is another source. Some waters are even described as “silicon-rich”. Diet, age and lifestyle are discussed in “Who needs silicon?”.

Is silicon safe?

The kidneys readily excrete absorbed silicon in urine [3]. In 2018, European food safety experts assessed vanillin-stabilised orthosilicic acid for use in supplements. They found no safety concerns for adults at the proposed intake, which provides 10–18 mg of silicon per day [11]. In two studies lasting 20 weeks and 9 months, women took choline-stabilised orthosilicic acid providing 10 mg of silicon per day. The authors reported no adverse events related to the supplement [8, 9].

If you have kidney problems, are pregnant, are breastfeeding or take medication, consult a doctor first. This also applies to children.

Silicon and blood vessel walls

Silicon is more often discussed in relation to skin or bones. But artery walls are also connective tissue. Collagen and elastin fibres give them strength and elasticity.

Scientific reviews published in 2013 and 2026 summarised what is known about the relationship between silicon and bone mineralisation, collagen synthesis, and the condition of skin and blood vessels [1, 2]. However, these data are not sufficient to draw conclusions about the clinical effects of silicon supplements on blood vessels. If you have come across a promise to “cleanse blood vessels”, it is misleading. We explain why in “Silicon and blood vessel health: what the research shows”.

Silicon and bones: what science tells us

Bone is made up of more than calcium. Its organic foundation is a collagen framework onto which minerals are deposited. This is why silicon is also studied in relation to bone health.

In the laboratory study (in vitro) mentioned above, orthosilicic acid promoted the maturation of cells similar to those that build bone [5]. Osteoclasts break down old bone tissue. In another laboratory study (in vitro, 2024), orthosilicic acid inhibited their formation, and less bone was resorbed in this model [19].

A monograph on silicon in water (Odesa National Medical University, 2026) also describes historical observations. At bone fracture sites where collagen fibrils were forming, silicon content increased up to 50-fold [13]. One of the monograph’s co-authors is this article’s reviewer, Andrii Mokiienko.

Why we chose OAOSA

When choosing a form of silicon for SILINEXT, we focused on the following:

• Form. Stabilised silicic acid in an acacia gum matrix.
• A clearly specified amount. According to the manufacturer’s specification, the silicon content of the raw material is standardised at 3%. So 500 mg of OAOSA provides around 15 mg of elemental silicon.
• Format. OAOSA is a powder, so it can be used in both capsules and sachets. This is how ACTIVATOR and MATRIX came about: they contain equal amounts of silicon, with different accompanying ingredients.

Who developed and manufactures this form also mattered. According to the manufacturer:

• OAOSA technology was developed by the Spanish company Silicium España Laboratorios (the LIVING SILICA® brand), which specialises in forms of silicon; the technology is protected by a patent [6];
• the company’s manufacturing operations in Spain follow FSSC 22000, ISO 22000 and current Good Manufacturing Practice (cGMP) standards for food supplements;
• the raw material is GMO-free and suitable for kosher and halal diets;
• the company’s products are exported to 50 countries (2025 catalogue).

We source the raw material directly from the manufacturer.

How much silicon is in a daily serving?

Both SILINEXT products, PRO COLLAGEN ACTIVATOR and PRO COLLAGEN MATRIX, contain 500 mg of OAOSA per daily serving, providing around 15 mg of elemental silicon. When comparing them with other supplements, look at the milligrams of elemental silicon, rather than the weight of the raw material or extract. For SILINEXT products, 15 mg of silicon is the standardised amount in a daily serving, not a universal daily requirement for everyone. In “Daily silicon intake”, we explain what the milligrams on a label mean and why there is no official daily intake for silicon.

NRV stands for Nutrient Reference Value.

Why do both products contain vitamin C? Vitamin C contributes to normal collagen formation for the normal function of skin.

Why does MATRIX contain zinc? Zinc contributes to the maintenance of normal skin, hair and nails. Zinc contributes to normal protein synthesis.

How much protein is in MATRIX? MATRIX is high in protein: more than 4.5 g of protein in each sachet. Its collagen peptides contain around 1 g of glycine, more than 0.5 g of proline and more than 0.4 g of hydroxyproline.

A varied, balanced diet and a healthy lifestyle are important for health. Do not exceed the recommended daily serving. Take into account zinc from other supplements and food: according to the European assessment, the upper limit for adults is 25 mg per day from all sources [20]. If you are pregnant or breastfeeding, consult a doctor before use.

ACTIVATOR or MATRIX: which should you choose?

Start by deciding whether you want collagen peptides in the product and which format suits you better: capsules or sachets. Both formulas contain the same OAOSA and the same amount of silicon.

The collagen in MATRIX comes from fish, so this product is not suitable for people with a fish allergy.

Compare the ingredients and formats on the SILINEXT PRO COLLAGEN ACTIVATOR and SILINEXT PRO COLLAGEN MATRIX product pages.

Frequently asked questions

Can you get silicon from mineral water? Yes, mineral waters contain silicon in a soluble form. In Ukraine, its content is regulated and measured as metasilicic acid (H₂SiO₃). Waters containing at least 50 mg/l of metasilicic acid are classified as silicon-rich [13]. How much silicon you get depends on the particular water.

Can you take silicon together with collagen? Yes. Silicon and collagen are different substances: collagen is a protein, while silicon is a trace element. They can be taken in the same product, or, if you already take collagen, you can take silicon separately.

How does OAOSA differ from ch-OSA? In its stabiliser and format. Both are forms of stabilised silicic acid, but OAOSA uses an acacia gum matrix, while the other form uses choline [6, 8]. The choline-stabilised form is available both as a liquid and as granules [4, 8]. OAOSA is a powder used to make capsules and sachets.

How much silicon do people get each day? From food, an average of 24–25 mg per day for women and 30–33 mg for men, according to the large Framingham study [17]. There is no official daily reference intake for silicon in the EU [18]. If you take a supplement, follow the daily serving on the label and do not exceed it.

Is it safe to take silicon every day? People already get silicon every day from food and water [13, 17], and absorbed silicon is excreted by the kidneys [3]. For supplements, experts assessed an orthosilicic acid–vanillin compound: they found no safety concerns for adults at the proposed intake (10–18 mg of silicon per day) [11]. For guidance on who should consult a doctor first, see “Is silicon safe?”.

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: 26 October 2026. Last scientific review: 21 August 2026. These dates refer to the Ukrainian source article.

References

1. 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)
2. Pan R, Zeng J, Wang X, Cui B, Deng C, Xu X, Chen ZY, Zhu H. Orthosilicic acid in functional foods: bioavailability, metabolism, and potential in degenerative disease prevention. Critical Reviews in Food Science and Nutrition. 2026;66(29):5977–5994. doi:10.1080/10408398.2026.2676108. PMID 42247212. (review)
3. 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.
4. 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.
5. Reffitt DM, Ogston N, Jugdaohsingh R, Cheung HF, Evans BA, Thompson RP, Powell JJ, Hampson GN. Orthosilicic acid stimulates collagen type 1 synthesis and osteoblastic differentiation in human osteoblast-like cells in vitro. Bone. 2003;32(2):127–135. doi:10.1016/S8756-3282(02)00950-X. PMID 12633784. (in vitro data)
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Younes M, Aggett P, Aguilar F, et al. Safety of orthosilicic acid-vanillin complex (OSA-VC) as a novel food ingredient to be used in food supplements as a source of silicon and bioavailability of silicon from the source. EFSA Journal. 2018;16(1):e05086. doi:10.2903/j.efsa.2018.5086. PMID 32625656.
12. 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)
13. 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.
14. Carlisle EM. Silicon: an essential element for the chick. Science. 1972;178(4061):619–621. doi:10.1126/science.178.4061.619. PMID 5086395.
15. Jugdaohsingh R, Tucker KL, Qiao N, Cupples LA, Kiel DP, Powell JJ. Dietary silicon intake is positively associated with bone mineral density in men and premenopausal women of the Framingham Offspring cohort. Journal of Bone and Mineral Research. 2004;19(2):297–307. doi:10.1359/JBMR.0301225. PMID 14969400.
16. Bisse E, Epting T, Beil A, Lindinger G, Lang H, Wieland H. Reference values for serum silicon in adults. Analytical Biochemistry. 2005;337(1):130–135. doi:10.1016/j.ab.2004.10.034. PMID 15649385.
17. Jugdaohsingh R, Anderson SHC, Tucker KL, Elliott H, Kiel DP, Thompson RPH, Powell JJ. Dietary silicon intake and absorption. American Journal of Clinical Nutrition. 2002;75(5):887–893. doi:10.1093/ajcn/75.5.887. PMID 11976163.
18. Regulation (EU) No 1169/2011 of the European Parliament and of the Council on the provision of food information to consumers. Annex XIII. EUR-Lex: CELEX 02011R1169-20250401.
19. Magnusson C, Ransjö M. Orthosilicic acid inhibits human osteoclast differentiation and bone resorption. PLOS One. 2024;19(10):e0312169. doi:10.1371/journal.pone.0312169. PMID 39405281. (in vitro data)
20. 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

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.