The trials were run on a drug that no longer exists. Strontium ranelate cut spinal fractures by about 41% in one trial 1 and non-spinal fractures by about 16% in another 2, in postmenopausal women over three years. Real reductions, smaller than the bisphosphonates already on the shelf, which cut spinal fractures 40 to 70% with decades of safety behind them.
The pill on the shelf is a different salt. The trials used ranelate; supplements sell strontium citrate, which has never gone through a fracture trial at any dose. The industry sells you the ranelate data on a molecule that was never tested that way.
The scan lies in your favour. Strontium is atom number 38; calcium is 20. The heavier atom absorbs more X-ray, so a little strontium in fresh bone reads as roughly 2.5 times the density of the same mass of calcium 3. Correct for it and the trial's headline bone gain roughly halves 4. Most scanners and clinicians never apply the correction, so the climbing number partly measures the pill inside your skeleton.
This is a decision, not a routine.
What actually builds and keeps bone costs less than the supplement. For osteoporosis, the first-line drugs are oral bisphosphonates; denosumab and the anabolic agents cover the harder cases, and none carries strontium's cardiovascular signal. For everyone else, the strongest lever bone has is mechanical load: resistance training, jumping, landing hard. Plus enough protein, calcium and vitamin D sufficiency (not megadoses), no smoking, and holding the drinking down. None of it is exciting, which is the honest reason the strontium aisle exists.
The fine print — when to skip it, and what people get wrong
Do not take strontium with a history of heart disease, heart attack or stroke, peripheral artery disease, uncontrolled high blood pressure, blood clots in legs or lungs, or reduced kidney function; skip it in pregnancy and breastfeeding 5.
Myths worth naming: a bone-density number climbing under strontium is about half artefact 3. Citrate is not the tested drug minus the patent; it's an untested salt. Strontium and calcium compete for uptake, so labels say separate them by two hours 6.
The quiet failure: years on citrate, a scan climbing, skipping the bisphosphonate on a corrupted number, until a low fall breaks a wrist or hip. The pill bought the feeling of doing something; it didn't buy the bone.
- 1Meunier PJ, Roux C, Seeman E, Ortolani S, Badurski JE, Spector TD, Cannata J, Balogh A, Lemmel EM, Pors-Nielsen S, Rizzoli R, Genant HK, Reginster JY (2004). The effects of strontium ranelate on the risk of vertebral fracture in women with postmenopausal osteoporosis. New England Journal of Medicine. link
- 2Reginster JY, Seeman E, De Vernejoul MC, Adami S, Compston J, Phenekos C, Devogelaer JP, Curiel MD, Sawicki A, Goemaere S, Sorensen OH, Felsenberg D, Meunier PJ (2005). Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis: Treatment of Peripheral Osteoporosis (TROPOS) study. Journal of Clinical Endocrinology and Metabolism. link
- 3Blake GM, Fogelman I (2007). Effect of bone strontium on BMD measurements. Journal of Clinical Densitometry. link
- 4Pors-Nielsen S, Slosman D, Sorensen OH, Basse-Cathalinat B, De Cassin P, Roux C, Meunier PJ (1999). Influence of strontium on bone mineral density and bone mineral content measurements by dual X-ray absorptiometry. Journal of Clinical Densitometry. link
- 5EMA (2014). PRAC recommends suspending use of Protelos/Osseor; subsequent restriction to severe osteoporosis without cardiovascular risk factors. link
- 6Reginster JY, Lecart MP, Deroisy R, Lousberg C (2003). Strontium ranelate: a new paradigm in the treatment of osteoporosis. Expert Opinion on Investigational Drugs. link
Strontium for Bone Density
A single daily capsule, with the constraint of separating from calcium-containing meals by at least 2 hours to avoid absorption competition (Reginster 2003). Trivial behavioural overhead.
OTC strontium citrate costs roughly $20-50/month at common doses (340-680 mg elemental Sr), or about $240-600/year ongoing. Sits in the $50-500/year minor range at the lower end and crosses into substantial at the upper end.
The pharmaceutical form (strontium ranelate) has two large phase III RCTs with positive fracture endpoints (Meunier 2004 SOTI; Reginster 2005 TROPOS) but was restricted (EMA 2014) and commercially withdrawn (Servier 2017) on cardiovascular safety grounds. The OTC supplement form (strontium citrate) — the form most readers actually buy — has no phase III fracture-endpoint RCT at any dose. The literature is mixed and contested: real but partly artefactual BMD gains (Blake and Fogelman 2007), real but small CV signal (Cooper 2014 vs Abrahamsen 2014 disagree on the post-marketing magnitude), and a complete absence of citrate-form trials. Mechanism is plausible (Marie 2001; Saidak and Marie 2012) but extrapolation across salts is not evidence.
The only fracture-endpoint evidence is for strontium ranelate (now withdrawn): pooled ~37% relative reduction in vertebral fracture and ~14% in non-vertebral fracture, with a hip-fracture effect confined to a high-risk subgroup (Kanis 2008; Meunier 2004; Reginster 2005). Once corrected for the DXA X-ray attenuation artefact, the underlying BMD gains are roughly half the raw numbers (Blake and Fogelman 2007). The EMA-documented MI signal (RR ~1.6, absolute increase ~0.4pp over 5 years; EMA 2014) offsets a meaningful fraction of the fracture-prevention longevity benefit. The OTC citrate form has no fracture-endpoint RCT data. Net longevity effect for the typical reader buying this supplement is marginal and possibly negative once cardiovascular risk is accounted for.