Home Ingredients Strontium (Citrate / Ranelate)
Bone Health

Strontium (Citrate / Ranelate)

Evidence Level
Moderate
2 Clinical Trials
4 Documented Benefits
3/5 Evidence Score

Strontium is a mineral chemically similar to calcium that incorporates into bone matrix. Strontium ranelate is approved as prescription osteoporosis drug in some European countries (Protelos®/Protaxos®) — but restricted IN 2014 due to cardiovascular and severe skin reaction concerns. Strontium citrate (the supplement form) is widely sold for bone health but lacks the same direct evidence as ranelate. Critical: distinct from radioactive strontium-90; supplemental strontium is non-radioactive natural strontium.

Studied Dose Strontium ranelate (prescription): 2 g/day; strontium citrate (supplement): 680 mg elemental strontium typical (in citrate form)
Active Compound Strontium (atomic number 38)

Benefits

Bone Mineral Density (Strontium Ranelate)

SOTI trial showed strontium ranelate 2 g/day reduced vertebral fractures by 41% vs placebo over 3 years in postmenopausal osteoporosis. TROPOS trial showed reduced non-vertebral fractures. Established strontium ranelate as evidence-based osteoporosis treatment in Europe — until safety concerns led to restriction in 2014.

Supported by Trial 1, Trial 2

Dual Action — Bone Formation and Resorption Inhibition

Distinguishes strontium from most other bone agents. Increases osteoblast (bone formation) activity and decreases osteoclast (bone resorption) activity. Most bisphosphonates only inhibit resorption.

Supported by Trial 1, Trial 2

Strontium Citrate (Supplement) Theoretical Effects

Strontium citrate is the typical supplemental form — provides similar elemental strontium to ranelate but not same drug. Theoretical bone-supportive effects via similar mechanism. Critical: strontium citrate lacks direct RCT evidence equivalent to ranelate; effects extrapolated from ranelate data.

Supported by Trial 1, Trial 2

DEXA Scan Artifact (False BMD Increase)

Critical consideration: strontium has higher atomic weight than calcium; even modest strontium incorporation into bone creates ARTIFACTUAL increase in DEXA bone density readings (~10% per 1% strontium content). This OVERESTIMATES true bone density gains with strontium. Real bone strength gains are smaller than DEXA suggests.

Supported by Trial 1

Mechanism of action

1

Bone Matrix Incorporation

Strontium substitutes for calcium in bone hydroxyapatite — creating strontium-containing bone matrix. Mechanism similar to calcium incorporation but with different physical properties.

2

Calcium-Sensing Receptor Modulation

Strontium activates calcium-sensing receptor (CaSR) on osteoblasts and osteoclasts — basis for dual action on bone formation and resorption.

3

Osteoblast Stimulation

Increases osteoblast number, activity, and bone formation markers. Distinct from bisphosphonates which only inhibit resorption.

4

Osteoclast Inhibition

Reduces osteoclast differentiation and activity — decreasing bone resorption.

Clinical trials

1
Strontium Ranelate for Osteoporosis — SOTI Trial

Phase 3 clinical trial of strontium ranelate 2 g/day vs placebo in 1,649 postmenopausal women with osteoporosis for 3 years.

1,649 postmenopausal osteoporosis patients.

41% reduction in vertebral fracture risk vs placebo. Established strontium ranelate as evidence-based osteoporosis treatment. Foundation for European prescription approval.

2
Strontium Ranelate Cardiovascular Safety Concerns

Pooled analyses of strontium ranelate trials examining cardiovascular events.

Pooled trial populations.

Increased risk of myocardial infarction, venous thromboembolism. Combined with severe skin reactions (DRESS syndrome cases) led to EMA restriction in 2014 — limited to severe osteoporosis where alternatives unavailable. Eventually withdrawn from many markets.

Side effects and drug interactions

Common Potential side effects

Strontium ranelate (prescription) — increased cardiovascular events (MI, VTE), severe skin reactions (DRESS syndrome, Stevens-Johnson), restricted use in EU 2014.
Strontium citrate (supplement) — generally better tolerated; cardiovascular safety less studied at typical supplement doses.
Nausea, diarrhea (initial).
Headache.
Dermatitis.
Memory disturbance rare.
DEXA artifact creating false-high BMD readings (consideration for monitoring).

Important Drug interactions

Calcium supplements — strontium and calcium compete for absorption; separate BY 2-3 hours minimum.
Tetracyclines, fluoroquinolones — strontium reduces absorption similarly to calcium; separate.
Levothyroxine — strontium reduces absorption; separate by 4 hours.
Iron, zinc, magnesium supplements — competition for absorption; separate.
Bisphosphonates (alendronate, etc.) — strontium may interfere; separate by hours.
Anticoagulants — minimal interaction.
Antibiotics that chelate divalent cations — separate.

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Frequently asked questions about Strontium (Citrate / Ranelate)

What is strontium used for?

Strontium (as strontium citrate in supplements) is taken for bone support, since it is chemically similar to calcium and is incorporated into bone. It is distinct from radioactive strontium; supplemental strontium is the stable, non-radioactive mineral.

Does strontium help with bone density?

A prescription form (strontium ranelate, used in some countries) has bone-density research, and supplemental strontium citrate is used similarly, though the evidence for the citrate form is weaker. Note that strontium can inflate bone-density scan readings because it is denser than calcium.

How much strontium should I take?

Supplemental strontium citrate is commonly used at around 680 mg of elemental strontium per day, mirroring studies of the ranelate form. Take it separately from calcium (by at least 2 hours), since they compete for absorption.

Is strontium safe?

Supplemental strontium is generally tolerated, but the prescription ranelate form has been linked to cardiovascular and clotting risks, leading to restrictions in some countries. Given these concerns, use strontium cautiously and discuss it with your doctor, especially with cardiovascular risk factors.

What is Strontium?

Strontium is a mineral chemically similar to calcium that incorporates into bone matrix. Strontium ranelate is approved as prescription osteoporosis drug in some European countries (Protelos®/Protaxos®) — but restricted IN 2014 due to cardiovascular and severe skin reaction concerns.

What is the recommended dosage of Strontium?

The clinically studied dose is Strontium ranelate (prescription): 2 g/day; strontium citrate (supplement): 680 mg elemental strontium typical (in citrate form) Always follow the product label and check with a healthcare provider for personal advice.

Is Strontium safe, and does it have side effects?

For most healthy adults, Strontium is well tolerated at studied doses. Reported effects can include: Strontium ranelate (prescription) — increased cardiovascular events (MI, VTE), severe skin reactions (DRESS syndrome, Stevens-Johnson), restricted use in EU 2014. It may also interact with some medications. Strontium is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Strontium interact with any medications?

Possible interactions include: Calcium supplements — strontium and calcium compete for absorption; separate BY 2-3 hours minimum. Tetracyclines, fluoroquinolones — strontium reduces absorption similarly to calcium; separate. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Strontium?

NutraSmarts rates the evidence for Strontium as Moderate (3 out of 5). It is backed by 2 clinical trials and 6 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(6 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Kanis JA, Johansson H, Oden A, McCloskey EV. A meta-analysis of the effect of strontium ranelate on the risk of vertebral and non-vertebral fracture in postmenopausal osteoporosis and the interaction with FRAX(®). Osteoporos Int. 2011;22(8):2347-55. doi: 10.1007/s00198-010-1474-0.PubMedUsed to support: Meta-analysis showing strontium ranelate reduced vertebral and non-vertebral fracture risk in osteoporosis. Note: this strong evidence is for the prescription drug strontium ranelate, not the strontium citrate sold as a supplement.
  2. Malaise O, Bruyere O, Reginster JY. Strontium ranelate normalizes bone mineral density in osteopenic patients. Aging Clin Exp Res. 2007;19(4):330-3. doi: 10.1007/BF03324710.PubMedUsed to support: Randomized trial in which strontium ranelate increased bone mineral density in osteopenic patients. Supports strontium's effect on bone density, again with the prescription ranelate form.
  3. Barrionuevo P, Kapoor E, Asi N, Alahdab F, Mohammed K, Benkhadra K, Almasri J, Farah W, Sarigianni M, Muthusamy K, Al Nofal A, Haydour Q, Wang Z, Murad MH. Efficacy of Pharmacological Therapies for the Prevention of Fractures in Postmenopausal Women: A Network Meta-Analysis. J Clin Endocrinol Metab. 2019;104(5):1623-1630. doi: 10.1210/jc.2019-00192.PubMedUsed to support: Systematic review of pharmacological therapies for fracture prevention in postmenopausal women, including strontium ranelate among effective agents. Context for the bone use.
  4. Tomczyk-Warunek A, Turżańska K, Posturzyńska A, Kowal F, Blicharski T, Pano IT, Winiarska-Mieczan A, Nikodem A, Dresler S, Sowa I, Wójciak M, Dobrowolski P. Influence of Various Strontium Formulations (Ranelate, Citrate, and Chloride) on Bone Mineral Density, Morphology, and Microarchitecture: A Comparative Study in an Ovariectomized Female Mouse Model of Osteoporosis. Int J Mol Sci. 2024;25(7):. doi: 10.3390/ijms25074075.PubMedUsed to support: Study comparing different strontium salts (ranelate, citrate, chloride) on bone mineral density. Directly relevant because supplements use strontium citrate, which has far less outcome evidence than ranelate.
  5. Reginster JY. Strontium ranelate in osteoporosis. Curr Pharm Des. 2002;8(21):1907-16. doi: 10.2174/1381612023393639.PubMedUsed to support: Review of strontium ranelate in osteoporosis, summarizing its dual action on bone formation and resorption. Background for the bone mechanism.
  6. Collette J, Bruyère O, Kaufman JM, Lorenc R, Felsenberg D, Spector TD, Diaz-Curiel M, Boonen S, Reginster JY. Vertebral anti-fracture efficacy of strontium ranelate according to pre-treatment bone turnover. Osteoporos Int. 2010;21(2):233-41. doi: 10.1007/s00198-009-0940-z.PubMedUsed to support: Meta-analysis of strontium ranelate's vertebral anti-fracture efficacy across baseline bone-turnover levels. Reinforces the bone evidence for the ranelate form. (Strontium ranelate was later restricted over cardiovascular safety, so supplemental strontium should be used cautiously.)