Your essential guide to silica: uses, benefits and side effects

Silica might not be a supplement you hear about every day, but this naturally occurring compound could have more to offer than you’d expect. Found in everything from sand to smoothies, let’s unpack what silica really is and whether it has real health benefits.

What is silica?

Silica, or silicon dioxide, combines two of the Earth’s most abundant elements: silicon and oxygen. It's a key component in construction materials like glass and concrete, but it's also naturally found in our food—think fruits, vegetables, grains, and even mineral water.

It’s basically all around us—but does it do anything for our bodies?

What are the possible benefits of silica?

Scientists are still piecing together exactly how silica functions in the human body. But early research suggests this trace mineral may contribute to our health in a few important ways, especially when it comes to bones, skin, hair, and nails.

Silica may support bone formation and maintenance

There’s evidence pointing to silica’s role in bone mineralisation—the process of layering minerals into bone tissue to keep it strong yet flexible. Some studies have linked higher silica intake with greater bone density, but the exact mechanism is still being investigated, and broader research is necessary to confirm these findings.

Silica may support collagen production

Often referred to as the “beauty mineral,” silica has gained attention for potentially helping with collagen synthesis. Collagen is essential for skin elasticity, and it also supports your joints and internal organs.

In one study, women with photodamaged skin who took 10mg of a bioavailable silica form daily for 20 weeks showed improvements in skin texture and reported less brittle hair and nails compared to a placebo group. Another study involving women with fine hair found silica supplementation over nine months led to thicker hair and fewer breakages.

While these results are promising, many of the studies so far have been small, and more rigorous research is needed to verify the broader beauty and health claims surrounding silica. Bioavailability and safety also require further exploration.

What are the sources of silica?

Silica primarily comes from plant-based foods. Good dietary sources include:

  • Unrefined grains
  • Cereal products
  • Fruits
  • Vegetables—especially green beans and leafy greens
  • Mineral water
  • Beer

Dietary supplements are another option, typically sourced from water-soluble silica forms found in horsetail and bamboo. Horsetail, a traditional herbal remedy, has historically been used for bone health and as a diuretic, though there’s limited human research backing these uses.

How much silica should you get?

No official guidelines currently exist for silica intake. There’s also no established upper limit due to a lack of evidence showing toxicity.

Still, one study suggests 25mg per day might be a reasonable target based on limited human and animal trials. However, due to insufficient safety data, silica supplements aren’t recommended for vulnerable groups such as:

  • Children (as horsetail may contain traces of nicotine)
  • Pregnant individuals
  • People with kidney disease (the body may struggle to eliminate excess silica)

Are there side effects of taking silica?

Silica from food doesn't appear to cause any adverse effects, and supplement use seems generally well tolerated among healthy adults, though there’s limited long-term safety data.

Horsetail-based supplements, however, have been linked to side effects in some cases, including:

  • Allergic reactions like skin rashes or facial swelling
  • Stomach discomfort
  • Low blood sugar levels (especially in people with type 2 diabetes)

If you’re considering taking silica supplements—especially if you have ongoing health conditions or take medications—have a chat with your GP first.

The final say

Silica shows up in everything from rocks to our diets, and it’s being studied for its potential health perks. Early evidence suggests it could help with bone strength and collagen production, but we’re still learning about how it works and how safe it is when consumed in supplement form.

As always, if you’re thinking about trying something new—especially something that’s not part of standard guidelines—it’s smart to get personalised advice from a healthcare professional.

Disclaimer

The advice in this article is for informational purposes only and should not be considered medical guidance. Always consult with a healthcare professional before starting any supplements, treatments, or remedies. Food supplements are not a substitute for a varied diet and healthy lifestyle.

At this time, scientific evidence on silica remains limited. While existing studies provide some insights, more clinical research is needed. Please speak to your GP before introducing new supplements.

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