Formulation: Strontium used to be a more common toothpaste additive to ease dental sensitivity. Over time it has fallen out of favor in the US and is being replaced by ingredients like potassium nitrate. Though there are some investigations into whether strontium chloride or nitrate may be useful in applications of skin sensitivities, these may also be difficult to find over the counter. In the US, strontium can be found in dietary supplements, most commonly as strontium citrate. Other forms of strontium sold over the counter as supplements include strontium chloride, strontium gluconate, strontium carbonate, strontium aspartate, and elemental strontium. Over the counter, strontium supplements are found in capsule, tablet, softgel, powder, and liquid forms.
Range of dosages studied: Oral strontium supplements currently on the market in the US range from 0.01–2,000 mg per day.[1]
For skin irritation and itching, strontium has been studied as a topical formulation that’s either 20% strontium nitrate or 4% strontium chloride, combined with other ingredients. For tooth hypersensitivity, pastes containing 2–10% strontium chloride or 8% strontium acetate have been studied.
Effective Dosages:
Skin Irritation/Itching
Adults: Direct application of a topical ointment containing either 20% strontium nitrate or 4% strontium chloride, combined with other ingredients (e.g., hydrocortisone, diphenhydramine, glycolic acid).[2][3][4]
Dental Sensitivity
Adults: Toothpaste containing 8% strontium acetate or 2–10% strontium chloride, for use twice per day in normal brushing.[5][6][7][8][9][10][11][12]
Other Considerations:
For other conditions (osteoarthritis, osteoporosis, bone-fracture risk) strontium ranelate has been studied as a pharmaceutical agent. Strontium ranelate is used by prescription in Europe for treating osteoporosis, but it is not currently approved by the US FDA because of concerns of cardiovascular risk. High levels of strontium exposure have been associated with calcium, phosphorus, and vitamin D deficiencies.[13]
For other forms of strontium as an oral, over-the-counter supplement, clinical evidence is lacking.
Supplement labels often recommend taking strontium and calcium supplements separately (often spaced at least 2–4 hours apart).[1] This makes sense, because our ability to absorb strontium decreases when taken in conjunction with calcium.[13][14]