A mineral chemically similar to calcium that deposits in bone. Strontium ranelate was a prescription osteoporosis drug in Europe; strontium citrate is sold over the counter as a supplement and has no trial evidence of its own.
Strontium is a cautionary tale about borrowed evidence. Strontium ranelate genuinely reduced vertebral and hip fractures in large randomised trials and was licensed in Europe for osteoporosis. It was then restricted in 2014 after regulators identified an increased risk of myocardial infarction and venous thromboembolism, alongside rare severe hypersensitivity reactions, and was withdrawn from the market in 2017 for commercial reasons after use had collapsed. The supplement sold today is strontium citrate — a different salt, at different doses, with no fracture trials — marketed on the ranelate results while omitting the reason ranelate was restricted. Strontium also has a distinctive practical problem: it is denser than calcium and inflates bone density scan readings, so a DXA result can improve substantially without any real change in bone strength.
Sold as
Capsule, Tablet, Powder, Component of bone formulas
Also known as
Strontium citrate, Strontium ranelate (prescription), Sr
Regulation: Strontium ranelate was restricted by the European Medicines Agency in 2014 over cardiovascular risk and withdrawn in 2017; it was never approved in the US. Strontium citrate is sold as a dietary supplement in the US with no pre-market efficacy or safety review. No RDA or Tolerable Upper Intake Level exists for strontium.
What the research used
The amounts, forms and durations published trials of Strontium (citrate) actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Strontium ranelate fracture trials
2 g
Strong
Strontium ranelate sachet, daily · 3–5 years
Reduced vertebral and hip fractures in postmenopausal osteoporosis. This is the evidence supplement marketing borrows, and it belongs to a different salt that regulators subsequently restricted for cardiovascular harm.
Studied for Typical retail strontium citrate
340–680 mg
Not enough
Elemental strontium, daily
No trial has tested strontium citrate for fractures or bone density at any dose. The amounts are chosen to approximate the elemental strontium in the ranelate regimen, which is an assumption rather than a finding.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
When it was taken
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
Each timing below was actually compared against an alternative in a trial, which is unusual.
🌙Evening
Moderate
Taken away from calcium and food because strontium and calcium compete directly for absorption — the ranelate product was specified to be taken at bedtime, at least two hours after eating. That instruction came from absorption studies.
Timing was tested. A trial compared this window against another and reported a difference.
The evidence in depth
Best supported: Not enough
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
Strontium ranelate reduced fractures in large trials, but the over-the-counter citrate salt has never been tested for any bone outcome. Strontium also artificially inflates bone density scan readings because it is denser than calcium, so an apparent improvement on a scan can be a measurement artefact rather than stronger bone.
What may be going on: Strontium substitutes for calcium in the bone mineral lattice and appears in laboratory work to both reduce bone resorption and support formation.
Not enough evidence. Not enough human research to say anything useful yet.
No source is attached to this association yet, so it is rated not enough evidenceby default. It is listed because people commonly ask about it — not because there is evidence for it.
Things to know
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Too much
Cardiovascular risk led to regulatory restriction
European regulators restricted strontium ranelate in 2014 after identifying an increased risk of myocardial infarction and venous thromboembolism, limiting it to severe osteoporosis in people without cardiovascular risk factors. The supplement industry markets the fracture data from those trials without the safety finding attached to it.
Worth knowing
Distorts bone density scan results
Strontium has a higher atomic number than calcium, so DXA overestimates bone mineral density in anyone taking it — by a substantial margin. A scan showing improvement may reflect strontium in the bone rather than more bone, which can lead to real osteoporosis being under-managed.
Worth knowing
Severe hypersensitivity reactions with ranelate
DRESS syndrome — a rare, potentially fatal drug reaction with rash, fever and organ involvement — was reported with strontium ranelate. Whether the citrate salt shares this is unknown because it has never been studied.
Strontium and calcium compete for the same absorption pathway, so they must be taken hours apart. Strontium also binds tetracyclines and fluoroquinolones, reducing their absorption.
Worth knowing
Kidney impairment and clotting risk
Strontium is cleared by the kidneys and is not advisable in significant kidney impairment. Given the thromboembolism signal with ranelate, it is a poor choice for anyone with a history of clots or prolonged immobility.