Strontium 300 mg by Klaire Labs/SFI Health

If you’re looking at strontium citrate for bone density because your DEXA scan shows low bone mass, this is the use-case. It’s most relevant for post‑menopausal women and older men with low bone density who already have their basics in place. Check Vitamin D, 25-Hydroxy and Calcium first and correct if low, since strontium is an add‑on, not a replacement for calcium, vitamin D, and weight‑bearing exercise. If your eGFR (kidney function estimate) is reduced, talk to your clinician before starting.

Strontium is a mineral that sits next to calcium on the periodic table, so it can swap into bone mineral and make the crystal lattice more resistant to breakdown. In cells, it nudges osteoblasts (the cells that build bone) to be more active and slows osteoclasts (the cells that resorb bone). That dual effect is why some people see favorable shifts in bone turnover markers like P1NP (formation) and CTX (resorption) within months. The catch is that DEXA overreads when strontium is present, so reported bone density can look higher than the true calcium-based density.

Take one capsule once or twice daily, away from calcium-containing foods or supplements. Strontium and calcium compete for the same transport, so separate them by at least two hours; bedtime on an empty stomach is practical for many. One capsule supplies 300 mg elemental strontium; two daily brings you near the 600–700 mg range commonly used in studies. Expect bone marker changes within 3–6 months and any DEXA changes at 6–12 months.

Avoid strontium if you have significant kidney disease, are pregnant or breastfeeding, or have a history of blood clots or uncontrolled cardiovascular disease. A prescription-only strontium salt (ranelate) showed higher cardiovascular events in high‑risk patients; while citrate is a supplement, the signal makes caution sensible. Separate by several hours from tetracycline or fluoroquinolone antibiotics and from levothyroxine, as strontium can bind these and block absorption. Tell your clinician you’re taking it before a follow‑up DEXA.

Will it replace calcium? No—keep dietary calcium steady and take calcium at a different time of day. Does it inflate DEXA? Yes, strontium in bone makes DEXA read higher, so interpret follow‑ups with that in mind. Can you track response sooner? Bone turnover labs like P1NP and CTX can show direction of change months before a scan. Should vegans use it? Possibly, but fix Vitamin D, 25‑Hydroxy and dietary calcium first.