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Dietary supplement

Strontium 300 mg Ingredients & Drug Interactions

by Klaire Labs

Strontium 300 mg label
See full label image
Capsule Category: Mineral
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Strontium 300 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Strontium 300 mg is a dietary supplement by Klaire Labs with 1 active ingredient. Its ingredients are commonly taken for bone health and osteoporosis, reducing fracture risk, tooth sensitivity (in some toothpastes).Based on those ingredients, 101 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Strontium. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Strontium 300 mg by Klaire Labs

Ask about any prescription or over-the-counter medication and we check it for interactions with Strontium 300 mg by Klaire Labs — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Strontium 300 mg by Klaire Labs

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: strontium at 300 mg per capsule. Strontium is a mineral that accumulates in bone and may support bone strength and help reduce bone pain.

The capsule also contains inactive ingredients (hydroxypropyl methylcellulose, water, ascorbyl palmitate, microcrystalline cellulose, and silicon dioxide) that serve as the capsule shell and stabilizers.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: mineral supplement for bone health.
  • We looked for evidence on: Osteoporosis, Fractures, Bone density, Fracture prevention.
  • The strongest evidence on file: Strontium is rated "Likely Effective" for Osteoporosis (Natural Medicines).
  • Also on file: Strontium is rated "Insufficient Reliable Evidence To Rate" for Fractures.

Strontium is rated Effective for dental hypersensitivity and for pain from bony metastases (cancer spread to bone). It's rated Likely Effective for osteoporosis, Possibly Effective for osteoarthritis, and Possibly Effective as a prostate cancer support.

The evidence is strongest for dental sensitivity and bone pain; for bone health and other uses, the data is less robust.

The evidence, ingredient by ingredient Strontium

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Strontium, especially the ranelate form, carries cautions around heart and clotting risk that you should know about. The most common side effects are mild—diarrhea, nausea, headache, and skin irritation—and appear in people taking doses up to 2 grams daily long-term.

However, clinical trials show strontium ranelate increases the risk of blood clots (venous thromboembolism and pulmonary embolism) by about 50% versus placebo, and may raise the risk of heart attack by roughly 1.6-fold in people with osteoporosis. These serious effects are rare but documented.

Strontium safety has not been established in pregnancy, so it's best avoided. There isn't enough safety data for breastfeeding either—talk with your doctor or pharmacist about whether it's right for you if you're pregnant or nursing.

Side effects, ingredient by ingredient Strontium

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Strontium.
  • The most serious interaction on file is rated Moderate.
  • For scale: 101 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you start strontium, check with your pharmacist if you take estrogens (including birth control), androgens or testosterone, antacids, quinolone antibiotics (like ciprofloxacin), or tetracycline antibiotics (like doxycycline). All interact at a Moderate level and may need timing adjustments to work safely and effectively.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Strontium may help with bone pain, dental sensitivity, and osteoporosis support, but it comes with documented risks of blood clots and heart problems that warrant a conversation with your doctor first. If you're on estrogens, androgens, antacids, or antibiotics, spacing and timing matter.

Your pharmacist can help you navigate the logistics and decide whether this is the right choice for you.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Dec 21, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Strontium 300 mg, straight from the product label.

Brand Klaire Labs
Barcode (UPC) 828054001732
Net contents 100 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Dec 21, 2024
DSLD ID 322457
Product type Mineral
Supplement form Capsule
Dietary claims / uses Nutrient, All Other
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Strontium 300 mg by Klaire Labs, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
100
UPC/BARCODE
828054001732
IngredientAmount% DV
Strontium300 mg--

Other ingredients: Hydroxypropyl Methylcellulose, Water, Ascorbyl Palmitate, Microcrystalline Cellulose, Silicon Dioxide

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formulation

Free of the following common allergens: milk/casein, eggs, fish, shellfish, tree nuts, peanuts, wheat, gluten, soybeans, and corn. Contains no artificial colors, flavors or preservatives.

Produced under a strict quality management system in compliance with Good Manufacturing Practices (GMPs) and third-party quality certifications.

Suggested/Recommended/Usage/Directions

Suggested Use: 1 capsule, 1 to 2 times daily with or between meals, away from calcium-containing food or supplements or as directed by a healthcare professional.

Formula

This product contains a stable form of strontium, an important mineral.

Precautions

Do not use if shrinkwrap is broken or missing.

Caution: If you are pregnant, nursing, have a medical condition, or taking prescription drugs, consult your physician before using this product.

Keep out of reach of children.

Storage

Store in a cool, dry place (59 degrees F - 85 degrees F) away from direct light.

FDA Statement of Identity

Mineral Supplement

General Statements

SFI

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Strontium 300 mg by Klaire Labs label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Strontium 300 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Strontium 300 mg by Klaire Labs

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container100 Amounts shown are per serving.

Strontium

Interacts with
101 drugs
300 mg per serving Form: Strontium Citrate

Strontium is a mineral that has been studied mainly for bone health and osteoporosis. The prescription form (strontium ranelate) showed benefit for fr...

Strontium monograph & interactions

Other (inactive) ingredients: Hydroxypropyl Methylcellulose, Water, Ascorbyl Palmitate, Microcrystalline Cellulose, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Strontium 300 mg by Klaire Labs Drug Interactions

Want to check YOUR meds against Strontium 300 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
101Drugs
101 Moderate

Ingredients driving the most interactions

Strontium 101

Individual Drug Interactions

The ingredients in Strontium 300 mg interact with 101 drugs. Click any drug to see the details.

1 of the 1 ingredient in Strontium 300 mg interact with drugs. Each result below shows which ingredient is responsible. Strontium

Each ingredient & the kinds of drugs it affects

For each ingredient in Strontium 300 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Strontium5 drug types · 101 drugs

Androgens

Theoretically, androgens might reduce the excretion of strontium, potentially increasing its effects and adverse effects.
A small clinical study suggests that treatment with androgens such as testosterone, nandrolone, oxandrolone, and oxymetholone for 5-6 weeks might decrease urinary strontium excretion. The clinical significance of this interaction is unknown.

Likelihood Possible Evidence D
Antacids

Antacids can reduce the absorption of strontium, potentially decreasing its effectiveness.
Aluminum hydroxide and magnesium hydroxide can reduce absorption of strontium ranelate by 20% to 25%. Calcium can reduce its absorption to 60% to 70%. Avoid taking antacids within 2 hours of a dose of strontium ranelate. This interaction has also been reported with orally-administered radioactive strontium-85. It will likely also occur with other forms of strontium.

Likelihood Probable Evidence C
Estrogens

Theoretically, estrogens might reduce the excretion of strontium, potentially increasing its effects and adverse effects.
A small clinical study suggests that treatment with estrogens for 5-6 weeks might decrease urinary strontium excretion. The clinical significance of this interaction is unknown.

Likelihood Possible Evidence D
Quinolone Antibiotics

Theoretically, strontium might decrease the absorption of quinolone antibiotics.
Strontium is a divalent cation with similar properties to calcium. It is likely to form complexes with quinolones in the gastrointestinal (GI) tract, preventing absorption of the antibiotic. Recommend taking strontium supplements at least 2 hours before or after quinolones to avoid an interaction.

Likelihood Probable Evidence D
Tetracycline Antibiotics

Theoretically, strontium might decrease the absorption of tetracycline antibiotics.
Strontium is a divalent cation with similar properties to calcium. It is likely to form complexes with tetracyclines in the gastrointestinal (GI) tract, preventing absorption of the antibiotic. Recommend taking strontium supplements at least 2 hours before or after tetracyclines to avoid an interaction.

Likelihood Probable Evidence D
Strontium full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Strontium 300 mg, from the product label.

Klaire Labs

See all Klaire Labs products
Name
SFI USA
City
Reno
State
NV
ZipCode
89521
Web Address
Klaire.com
Pharmacist Counseling Corner

Strontium 300 mg by Klaire Labs: Common Questions

Does Strontium 300 mg by Klaire Labs interact with any medications?
Yes. Based on its ingredients, Strontium 300 mg has a known interaction with 101 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Strontium 300 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What is strontium used for?
Strontium is most proven for dental sensitivity and bone pain from cancer. It's also used for osteoporosis (where it's likely effective), osteoarthritis, and prostate cancer support (where evidence is less certain). It accumulates in bone and may help strengthen it.
Can I take strontium with my antacid?
Not at the same time. Antacids can cut strontium absorption significantly—calcium-based ones block up to 60–70% of it. Take your strontium at least 2 hours before or after your antacid.
What are the most common side effects?
Diarrhea, nausea, headache, and skin irritation (dermatitis or eczema) are the most frequent. They tend to occur with regular long-term use, though most people tolerate strontium well at standard doses.
Is strontium safe in pregnancy or while breastfeeding?
Safety data is not established for pregnancy, so it's best avoided. There also isn't enough information to know whether it's safe while breastfeeding. Talk with your doctor or pharmacist about your individual situation before using it.
Are there serious risks I should know about?
Yes. Clinical trials show strontium, particularly strontium ranelate, can raise the risk of blood clots by about 50% and may increase heart attack risk by roughly 1.6-fold in people with osteoporosis. These are rare but documented—discuss your personal risk with your doctor before starting.
Does strontium interact with antibiotics?
Yes. Quinolone antibiotics (like ciprofloxacin) and tetracycline antibiotics (like doxycycline) may absorb poorly when strontium is present. Separate your doses by at least 2 hours.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Strontium 300 mg label
Go deeper

The Full Monographs Behind Strontium 300 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Strontium

Interacts with 101 drugs

Strontium is a mineral that has been studied mainly for bone health and osteoporosis. The prescription form (strontium ranelate) showed benefit for fracture risk but carries serious heart-re...

Read the full Strontium monograph →
Sources

Sources & How We Checked

Strontium 300 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 22 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Strontium 22 references
  1. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
  2. Meunier PJ, Roux C, Seeman E, et al. The effects of strontium ranelate on the risk of vertebral fracture in women with postmenopausal osteoporosis. N Engl J Med 2004;350:459-68.. PubMed
  3. El-Hajj Fuleihan G. Strontium ranelate--a novel therapy for osteoporosis or a permutation of the same? N Engl J Med 2004;350:504-6. PubMed
  4. Verberckmoes SC, De Broe ME, D'Haese PC. Dose-dependent effects of strontium on osteoblast function and mineralization. Kidney Int 2003;64:534-43. . PubMed
  5. Meunier PJ, Slosman DO, Delmas PD, et al. Strontium ranelate: dose-dependent effects in established postmenopausal vertebral osteoporosis--a 2-year randomized placebo controlled trial. J Clin Endocrinol Metab 2002;87:2060-6.. DOI
  6. Brandi ML. New treatment strategies: ipriflavone, strontium, vitamin D metabolites and analogs. Am J Med 1993;95:69S-74S. . PubMed
  7. Eisenberg E. Effects of androgens, estrogens and corticoids on strontium kinetics in man. J Clin Endocrinol Metab 1966;26:566-72.
  8. Metastron prescribing information. Medi-Physics, Inc., Amersham Healthcare, Arlington Heights, IL, 1998. http://www.cancerpaintherapy.com/METATECHPAGE.htm. (Accessed 13 March 2004).
  9. Protelos European Summary of Product Characteristics. Les Laboratoires Servier, 2006. Available at: www.servier.com/pro/osteoporose/protelos/protelos_spc.asp. (Accessed 01 August 2006).
  10. US Department of Health and Human Services, Public Health Service. Agency for Toxic Substances and Disease Registry. Toxicological profile for strontium. April 2004. Available at: www.atsdr.cdc.gov/toxprofiles/tp159.pdf. (Accessed 8 August 2006).
  11. Apostolidis N, Paradellis T, Karydas A, et al. Calcium and strontium metabolic studies in patients on CAPD. Perit Dial Int 1998;18:410-4. DOI
  12. Ozgur S, Sumer H, Kocoglu G. Rickets and soil strontium. Arch Dis Child 1996;75:524-6. PubMed
  13. Schrooten I, Elseviers MM, Lamberts LV, et al. Increased serum strontium levels in dialysis patients: an epidemiological survey. Kidney Int 1999;56:1886-92. PubMed
  14. D'Haese PC, Couttenye MM, Lamberts LV, et al. Aluminum, iron, lead, cadmium, copper, zinc, chromium, magnesium, strontium, and calcium content in bone of end-stage renal failure patients. Clin Chem 1999;45:1548-56. DOI
  15. Pennington JA, Jones JW. Molybdenum, nickel, cobalt, vanadium, and strontium in total diets. J Am Diet Assoc 1987;87:1644-50. DOI
  16. O'Donnell S, Cranney A, Wells GA, et al. Strontium ranelate for preventing and treating postmenopausal osteoporosis. Cochrane Musculoskeletal Group. Cochrane Database Syst Rev 2006;(4):CD005326. PubMed
  17. Protelos European Public Assessment Report, Scientific Discussion. European Medicines Agency, 2005. Available at: www.emea.eu.int/humandocs/Humans/EPAR/protelos/protelos.htm. (Accessed 10 October 2006).
  18. Rousselet F, El Solh N, Maurat JP, et al. Strontium and calcium metabolism. Interaction of strontium and vitamin D. C R Seances Soc Biol Fil 1975;169:322-9.
  19. O'Donnell, S., Cranney, A., Wells, G. A., Adachi, J. D., and Reginster, J. Y. Strontium ranelate for preventing and treating postmenopausal osteoporosis. Cochrane.Database.Syst.Rev. 2006;3:CD005326. PubMed
  20. Rizzoli R, Chapurlat RD, Laroche JM, et al. Effects of strontium ranelate and alendronate on bone microstructure in women with osteoporosis. Results of a 2-year study. Osteoporosis Int. 2012. 23(1):305-315. doi: 10.1007/s00198-011-1758-z. PubMed
  21. Reginster JY, Kaufman JM, Goemaere S, et al. Maintenance of antifracture efficacy over 10 years with strontium ranelate in postmenopausal osteoporosis. Osteoporos Int. 2012;23(3):1115-1122. doi: 10.1007/s00198-011-1847-z. PubMed
  22. Protos [Product Information]. Available at: http://www.guildlink.com.au/gc/ws/servier/pi.cfm?product=sepproto. Accessed May 1, 2018.

See these in context on the Strontium monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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