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Limited evidenceJoints & skin

Pearl Powder

Ground pearl, used for centuries in Chinese medicine as a beauty tonic. It is over 90% calcium carbonate with a small protein fraction, and there are no human trials for skin.

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What the science says

  • Skin appearance and anti-ageing Limited evidence

    No randomized or controlled human trial of oral or topical pearl powder for skin appearance, pigmentation or ageing is indexed in PubMed. The beauty reputation is entirely traditional.

  • Antioxidant activity in animals Limited evidence

    A 2026 characterisation study gave pearl powder orally to mice for four weeks and reported dose-dependent increases in tissue antioxidant capacity, with no toxicity at up to 500 mg/kg. The work was done in mice by researchers holding a patent on pearl powder antioxidants, and no clinical study has followed.

  • Mineral content Limited evidence

    Physicochemical characterisation confirms pearl powder is predominantly calcium carbonate with trace minerals and conchiolin proteins. As a calcium source it is unremarkable and far more expensive than standard calcium carbonate.

Dosage & safety

Studied doseNo clinical dose exists. Traditional use is 0.3–1 g/day of finely ground powder; product labels commonly suggest 500 mg/day.
SafetyCalcium carbonate is well tolerated but can cause constipation and, in large amounts, interfere with iron and zinc absorption. Pearl and shell products have been reported to carry heavy metal contamination in some markets, so third-party testing matters. Avoid if you have hypercalcaemia or are already taking high-dose calcium.

How to take it

TimingTiming does not matter; split larger amounts across the day.
With food?Take it with a meal — calcium carbonate dissolves properly only in an acidic stomach.
Worth knowingBuy only third-party heavy-metal-tested product: pearl and shell powders have repeatedly turned up contaminated in market surveys.

Interactions

With medications

  • levothyroxine

    The calcium carbonate in pearl powder binds levothyroxine and reduces absorption. separate by at least 4 hours

  • tetracycline and quinolone antibiotics

    Calcium chelates these antibiotics and can markedly reduce their absorption. take the antibiotic 2 hours before or 4 to 6 hours after

  • proton pump inhibitors and other acid reducers

    Calcium carbonate needs stomach acid to dissolve, so absorption drops when acid is suppressed. take it with a meal, or use a calcium citrate product instead

With other supplements

  • iron and zinc supplements

    Calcium competes with both for absorption in the same dose. separate by at least 2 hours

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does pearl powder improve skin?

No controlled human trial has tested oral or topical pearl powder for skin appearance, pigmentation or ageing, so its beauty reputation is traditional and the evidence is limited. The only supporting research is a mouse study on antioxidant capacity.

What is pearl powder made of?

Pearl powder is over 90% calcium carbonate, with trace minerals and a small conchiolin protein fraction. As a calcium source it is unremarkable and far more expensive than standard calcium carbonate.

Is pearl powder safe to take?

The calcium carbonate in pearl powder is generally well tolerated but can cause constipation, and pearl and shell powders have been found contaminated with heavy metals in some markets. Buy only third-party tested product, and avoid pearl powder if you have hypercalcaemia or already take high-dose calcium.

Does pearl powder interact with medications?

Yes: the calcium in pearl powder reduces absorption of levothyroxine (separate by at least 4 hours) and of tetracycline and quinolone antibiotics (take the antibiotic 2 hours before or 4 to 6 hours after). Acid-reducing drugs also lower its absorption.

Scientific references

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