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Strontium — The Complete Supplement Guide

A bone-seeking mineral with one prescription form that actually works — and a cautionary tale about heart safety and the difference between ranelate and the rest.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden) Last reviewed July 2026

SupplementsMineralsStrontium

Strontium sits just below calcium in the periodic table — and in the body, it behaves similarly: it's deposited in bone. One specific form, strontium ranelate, has solid trial evidence for reducing fractures. Over-the-counter strontium supplements (citrate, chloride) are a different story entirely. For the dietary overview, see the Minerals page.

Read first. Strontium ranelate is a prescription drug in Europe, restricted to severe osteoporosis due to increased risk of heart attack and blood clots. Over-the-counter strontium is not the same thing and has no fracture-prevention evidence. This page describes what the science says — it is not a recommendation to self-supplement.

What it does

Strontium is not an essential nutrient — you don't need it to live. But it has a unique property: it's chemically similar enough to calcium that bone-building cells (osteoblasts) incorporate it into the bone matrix. At the same time, it appears to reduce bone resorption (the breakdown of bone by osteoclasts). This dual action — more building, less breakdown — is what made strontium ranelate an effective osteoporosis drug.1 Trace amounts of stable strontium occur naturally in food (seafood, root vegetables, grains) and in your bones.

Forms — the critical distinction

Not all strontium is the same. This is the single most important thing to understand:

Strontium ranelateThe prescription form (Protelos/Osseor in Europe). Two large trials — SOTI and TROPOS — showed it reduced vertebral fractures by 41% and non-vertebral fractures by 16% over 3 years in postmenopausal women with osteoporosis.2 Contains ranelic acid as the carrier. Restricted to severe osteoporosis due to cardiovascular risk.
Strontium citrate / chlorideOver-the-counter forms sold as bone health supplements. No fracture-prevention trials exist. The strontium is the same element, but the carrier molecule differs and the evidence base is zero. You cannot assume OTC strontium does what ranelate does.
SummaryStrontium ranelate works — with real cardiovascular risks attached. OTC strontium is an evidence-free zone. These are not interchangeable.

The evidence

The SOTI trial (1 649 women, 3 years) showed strontium ranelate 2 g/day reduced the risk of new vertebral fractures by 41% (RR 0.59, 95% CI 0.48–0.73) compared to placebo.2 TROPOS (5 091 women, 3 years) found a 16% reduction in non-vertebral fractures (RR 0.84, 95% CI 0.70–0.99).3 Bone mineral density (BMD) increased because strontium is denser than calcium — part of the BMD gain is real, and part is an artefact of the heavier atom sitting in bone. Post-marketing studies then showed an increased risk of myocardial infarction (RR ~1.6) and venous thromboembolism, leading the European Medicines Agency to restrict it to patients who cannot use other osteoporosis drugs.4 OTC strontium (citrate/chloride) has no equivalent trial data — no fracture studies, no long-term safety registry.

Intake & dose

DietNo RDA exists — strontium is not essential. Typical Western diets supply 1–5 mg/day from seafood, grains and root vegetables.5
PrescriptionStrontium ranelate 2 g/day (providing ~680 mg elemental strontium), taken at bedtime on an empty stomach, at least 2 hours after food/calcium. European prescription only.
OTCCommon doses of strontium citrate are 340–680 mg strontium/day. No established safe or effective dose exists for OTC forms. Calcium and strontium compete for absorption — take at separate times.

Toxicity & safety

The safety concerns around strontium ranelate are well documented:4

  • Cardiovascular: increased risk of myocardial infarction (~60% relative increase)
  • Venous thromboembolism: increased risk of blood clots (DVT and pulmonary embolism)
  • Drug reaction with eosinophilia and systemic symptoms (DRESS): a rare but serious hypersensitivity syndrome

For OTC strontium, the risks are unknown — not absent, simply unstudied. The element accumulates in bone with a half-life of years, so any adverse effect could be slow to emerge and slow to reverse.

Bottom line: strontium ranelate is an effective but restricted prescription osteoporosis drug. OTC strontium (citrate/chloride) has no fracture evidence and unknown long-term safety — it is not a substitute for the drug and should not be treated as one.

References

Adult research summary for education, not a prescription.

  1. Marie PJ, Felsenberg D, Brandi ML. How strontium ranelate, via opposite effects on bone resorption and formation, prevents osteoporosis. Osteoporos Int 2011;22(6):1659–67. PubMed 21165601
  2. Meunier PJ et al. The effects of strontium ranelate on the risk of vertebral fracture in women with postmenopausal osteoporosis (SOTI). N Engl J Med 2004;350(5):459–68. PubMed 14749454
  3. Reginster JY et al. Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis (TROPOS). J Clin Endocrinol Metab 2005;90(5):2816–22. PubMed 15728210
  4. European Medicines Agency. Protelos/Osseor — Article 20 referral: restrictions in use due to increased risk of myocardial infarction. EMA/258269/2013. ema.europa.eu
  5. EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on Dietary Reference Values for strontium — not established as an essential nutrient. EFSA Journal 2014.

This article summarises clinical trial evidence for education. It is not a substitute for individual medical advice. Strontium ranelate is a prescription drug — never self-medicate with OTC strontium in its place.