Strontium Ranelate vs Strontium Citrate

Updated: October 20, 2022

Pills on open hand

Osteopenia and osteoporosis patients are often confused when their doctor recommends strontium for them. Patients then typically read up information about strontium, come across sensational write ups that misinform and create fear for Strontium. Doctors usually prescribe either of the two variants strontium ranelate or strontium citrate. After doing some of their own spade work, patients then begin to wonder why they were not prescribed the other form.

First let’s begin by dispelling the fear of strontium. Strontium is a naturally occurring silvery white or yellowish mineral found in the soil, and it has some serious health benefits. People who consume organic and farm produce usually get enough of this mineral and do not require strontium supplements. You can find out more about strontium-rich foods on our dedicated strontium food sources page. In it’s natural state strontium is a stable metal element of alkaline nature (atomic weight 38). It is non-toxic and non-radioactive. Its man-made isotope strontium (atomic weight 90) is radioactive. Like calcium, strontium is a Group 2 element in the periodic table and is placed just beneath calcium. In other words, it’s chemical properties and behaviour are very similar. (1)

Now let us look at the prescribed variants – strontium ranelate and strontium citrate. They are both strontium salts. Strontium ranelate is composed of two atoms of stable strontium (natural) and a molecule of ranelic acid (synthetic/man-made). Strontium citrate is composed of two atoms of strontium and a molecule of citric acid.

So why is it that citrate or ranelate salts are prescribed? This brings us to the absorption issue. Studies have shown that citrate salt of strontium is more readily absorbed in the gastrointestinal tract as compared to strontium carbonate or other strontium salts. However, strontium ranelate is known to be more bioavailable (chemical that is eventually able to reach systemic circulation). Studies have proved that the bioavailability of strontium ranelate is 25% after a 2-gram dosage administration. (2)

It is possible that strontium ranelate gives mild undesirable side effects such as nausea, diarrhea, headaches and eczema/rash. However, they are said to resolve after a few weeks of starting strontium ranelate. Chances of experiencing side-effects with strontium ranelate are marginally more than with strontium citrate.

Strontium ranelate is prescribed for young men and post-menopausal women only. It’s usage is contraindicated in pregnant and lactating women. Strontium ranelate is also not to be prescribed to persons who suffer from kidney conditions, thrombo-embolism or phenylketonuria (rare condition in which a person has the inability to break down the amino acid phenylalanine). It is not to be prescribed for children. (3)

Strontium ranelate is not available over the counter. It is classified as a drug/medicine and so can be bought on a doctor’s prescription only. Strontium citrate on the other hand, is categorized as a supplement and may be bought over the counter.

Strontium ranelate is almost twice as expensive as strontium citrate and almost six times more expensive than standard bone-building medication.

Strontium ranelate is manufactured and marketed by the French pharmaceutical company Servier Laboratories under the brand name Protelos. It is available in some European countries and in Asia. Strontium ranelate has not yet been approved by the American Food and Drug Administration and is thus not sold in the U.S. Strontium citrate is available worldwide and is sold by AlgaeCal, Nature’s Purest, Doctor’s Best, Bio Tech Pharmacal, Pure Encapsulations (Atrium Innovation Inc). Strontium is available in several strengths/potencies. Your doctor will advise you on the milligrams per dose you require and the timing you should observe while taking either of the two strontium salts (Read AlgaeCal article on how strontium supplements are to be taken on an empty stomach and apart from calcium supplements).


  1. Evidence-Based Perspectives on Hot Women’s Health Issues;; december, 2011;
  2. Summary Of Product Characteristics, Interaction with other medicinal products and other forms of interaction (Page 4);; December, 2011;
  3. Find A Vitamin or Supplement; WebMD; December, 2011;


  1. Strontium Citrate Safety; National Osteoporosis Foundation – Support Community; December, 2011;
  2. Strontium Citrate: A Natural Treatment for Osteoporosis; Osteoporosis & Vitamins; December, 2011;
  3. Strontium ranelate; Wikipedia; December, 2011;


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  1. Rita Smith

    February 17, 2012 , 8:23 am

    I am a 60 year old woman who does not have osteoporosis but I am on Ultimate Bone Support. Composition, Vitamins D3,K2 Zinc, copper, Manganese,-Boron, Silicon, Strontium citrate, L-Lysine, Hops. Is it ok to keep taking them because my doctor told me that they cannot be Bio if there is strontium in the supplements as strontium is prescribed for osteoporosis patients and she added that it is medicinal and treatment. Is that true? So do I stop taking them?

    Rita Smith

  2. julie

    June 27, 2012 , 10:04 am

    Is Strontium boost safe to take if you have epilepsy?

  3. bruce

    December 8, 2012 , 7:46 am

    Our 19 yr old son has recently suffered a fractured scaphoid. unfortunately it has been problematic in healing. The cast has been removed now (after 10 weeks and three different casts). The fracture remains, but less so. The very competent Orthopedic Specialist sent him for a CT scan and compared to the Xrays taken has concluded he has Osteopenia. He is 2000 km away at university so my doctor has suggested we get him onto a regime of Strontium Citrate 550 mg twice daily with 2000 units D3 & 300mg of Calcium Citrate thrice daily. Also, get the bone density test done when he’s home for Christmas. Any input would be appreciated. Thanks from afar. Bruce

  4. urooj

    December 24, 2012 , 10:14 pm

    Hello I’m Dr Urooj lives in Karachi Pakistan.and my father had a fracture at intertrochantric area in Dr has prescribed him strontium..he has a weak union .he,s diabetic since 15yrs on oral sulphonylurea.and well there is a risk factor of thromboembolism.although he.s walking with the help of a walker non weight bearing movement is advised.I’m bit confused about strontium is it good for him.

  5. ray hendle

    January 1, 2013 , 4:01 pm

    re: In it’s natural state Strontium is a stable metal element of alkaline nature (atomic number 38). It is non toxic and non-radioactive. It’s man-made isotope Strontium (atomic number 90) is radioactive.

    This is incorrect. All isotopes of Sr have Atomic No. 38. It’s the Mass number that varies (number of neutrons). The Mass Number is 90 for the radioactive Strontium… not the Atomic Number.

  6. ray hendle

    January 1, 2013 , 4:04 pm

    By the way, my wife has used your product several years. To date she has displayed significant improvement (confirmed medically).
    Thank You.

  7. Eliot W. Collins

    August 27, 2014 , 8:06 am

    Can taking strontium citrate cause kidney stones?

  8. Monica

    August 27, 2014 , 2:21 pm

    Hi Eliot,

    Strontium citrate does not cause kidney stones. Not a single study has ever shown that strontium citrate causes venous thromboembolism (VTE) or any blood clots or DRESS syndrome. Only strontium ranelate has been found to produce these adverse effects.

    – Monica @ AlgaeCal

  9. Eliot W. Collins

    August 28, 2014 , 6:56 am

    Thanks Monica.

  10. Dr. Sickels

    September 24, 2014 , 3:09 pm

    The radioactive strontium’s got a higher atomic _weight_ (90), not atomic number. The atomic number is the number of protons, while the weight is the protons + neutrons, and it’s the increased weight that makes an element unstable and radioactive. [upon perusal of the other comments, I see that someone corrected you on this already, sorry to nag you about it]

    Also, saying that strontium citrate hasn’t been shown to cause VTE or other things is a bit disingenuous, since there’s only been 2 studies on strontium citrate in humans (in addition to one study on rats and one on zebrafish), with a total number of subjects of 11. A more honest answer would be that we don’t know because there is no data. There’s also no data to show that it doesn’t cause kidney stones, not is there to say that it does, so an accurate response would be to say that there’s no published data, but (if this is your experience) we haven’t seen it happen.

  11. Lara Pizzorno

    October 3, 2014 , 10:30 am

    Hello Dr. Sickels,

    Thank you for taking the time to write in. Yes, a correction should be made to the blog discussing strontium since any form of strontium, stable as well as radioactive strontium, has a higher atomic weight not number. I greatly appreciate your noting this; the correction will be made.

    Regarding strontium citrate – I base the assertion that natural forms of strontium do not cause VTE on the very thorough 161-page report published by the Centers for Disease Control’s Agency for Toxic Substances and Disease Registry (Reference: Centers for Disease Control’s Agency for Toxic Substances and Disease Registry Health Effects of Strontium report accessible @ ) in which the following statement is made:

    “There is no direct evidence that strontium is toxic to humans, but there is suggestive epidemiological evidence that the oral toxicity observed at high doses in juvenile laboratory animals may pertain to humans under special circumstances. At low exposure levels, ingestion of stable strontium poses no harm to organisms with access to adequate calcium, phosphorus, and vitamin D. At higher exposure levels, especially under conditions of inadequate calcium, phosphorus, and vitamin D, stable strontium will interfere with normal bone development, causing ‘strontium rickets’ of variable severity.”

    No reports of VTE induced by strontium had ever been made until strontium ranelate was created, patented and prescribed – and no reports – not even one case report –of strontium citrate causing VTE have been made to date, despite many individuals having used this natural form of stable strontium. No reports of strontium citrate ever causing nephritis, much less kidney stones, have been made either. The adverse effect of nephritis has been seen only with strontium ranelate.

    You are correct in that no large scale studies have been conducted using strontium citrate. The reason for this is that such studies are extremely expensive, and natural compounds cannot be patented, so no financial incentive exists to conduct such trials. However, it is my educated opinion that if strontium citrate had ever caused VTE or nephritis or had even been suspected of possibly contributing to VTE or nephritis in even one individual, a case report would have been published and discussed in many journals, and media coverage would have been extensive. Not a single report of strontium citrate causing VTE or nephritis has been made. Applying your logic, that we should therefore say there is no data, we would have to say about any substance, e.g., aspirin, for which no data has ever been published indicating that it causes VTE or kidney stones that we’re just not sure as we have no data. This is logically correct, but practically of little use.

    Regarding reported side effects of strontium citrate, I have heard from 2 individuals who informed me that they developed an itchy rash shortly after beginning to take strontium citrate. The rash quickly went away when they stopped taking it. Each of us is unique, so even if many hundreds of thousands of people have used something, and no reactions have been seen, it is always advisable to carefully monitor the response of your body to any medication or natural supplement and to discontinue use if you suspect an adverse reaction. Given the potential bone-building benefits to be derived from the use of strontium citrate, and its excellent safety record, however, I would not hesitate to recommend a trial use of this supplement.

  12. Dee

    January 11, 2017 , 6:13 pm

    My 75 year old mom has been taking Calcium each morning and Strontium every evening. She broke her humorous bone directly under her rotary cuff and the bone was partly broken and twisted. She was given 2 options, surgery with pins and plate or leave it . Although she has osteopenia (which most people have) she does not have diabetes and decided to let nature take its course. After 3 weeks I was AMAZED at the amount of growth took place around the broken area which gave me hope for her as well as myself. I went out and purchased a bottle of Strontium Citrate right away!

  13. Ray

    February 13, 2017 , 3:13 pm

    Many thanks Monica – appreciate your quick reply.
    Kind regards.

  14. Pamela

    July 29, 2017 , 8:08 pm

    Hi , I can not have Menieres can’t have salt. Is strontium citrate salt? I have been having vertigo after taking algae cal and stontium . Not sure if they are the cause.

  15. Lara Pizzorno

    August 2, 2017 , 4:11 pm

    Hi Pamela,

    Strontium citrate does not contain sodium, which is the type of salt you must avoid: sodium chloride. You need to avoid sodium because it promotes fluid retention, and fluid retention in the inner ear contributes to the vertigo experienced in Meniere’s disease.
    Strontium citrate is a mineral salt, but not a sodium-containing mineral salt.

    The term “mineral salt” refers to the stable forms in which all minerals – whether strontium, calcium, magnesium, sodium, etc. — are found in nature. Minerals are never found alone. Minerals are cations (elements with a positive charge) and must combine with an anion (a compound with a negative charge) to be stable. So, minerals are always found bound to another negatively charged chemical compound, for example, citrate, carbonate, oxide, gluconate, lactate, aspartate – or in the case of table salt, chloride. These combinations of a mineral + one of these compounds are called mineral salts.

    When you consume any mineral salt, the mineral element becomes freed from its stabilizing partner during digestion and ionized (made soluble), so the mineral can be absorbed. Some stabilizing partners release more easily from their mineral than others. One that releases quite easily is citrate, which helps ensure that the strontium in strontium citrate is readily released and can be well absorbed from your digestive tract. Plus, citrate promotes a more alkaline pH, an additional beneficial effect when strontium is taken in the form of the mineral salt, strontium citrate.

    Neither AlgaeCal Plus nor Strontium Boost contains sodium, nor any other compound that would promote fluid retention, so neither should be a cause of your vertigo. To determine what is causing it, you might want to keep a detailed record of what you are eating and drinking for a few days to see how much sodium (table salt) you are consuming, and you may be surprised to discover you are ingesting far more than you realized. Many processed foods – canned foods, frozen foods, deli meats, snack bars, chips, crackers, even condiments like ketchup, etc – contain surprisingly large amounts of sodium.

    I very much hope this helps and please do keep me posted on what you discover,
    Lara @ AlgaeCal

  16. marlyn slavin

    August 6, 2018 , 4:03 pm

    Should one have labs done to assess strontium levels in the blood after taking strontium citrate for a number of years.
    What is safe?
    Can the level become toxic?

    Can the level be toxic?

  17. Jenna AlgaeCal

    August 15, 2018 , 1:06 pm

    Hi Marlyn,

    We’re glad you reached out! When taking the bone building dosage of 680 mg strontium citrate correctly (with adequate calcium supplementation, such as AlgaeCal Plus), it’s not necessary to have follow up testing to assess your strontium levels.

    In this article, Lara Pizzorno reviews the most recent research on strontium that supports its safety and effectiveness! We also have a recently completely 7-year long trial including AlgaeCal Plus and Strontium Boost that showed no side effects along with consistent and linear increases in bone mineral density all the way up to 7 years.

    If you have any questions please don’t hesitate to email [email protected] or give our Bone Health Consultants a call at 1-800-820-0184!

    – Jenna @ AlgaeCal

  18. Holly

    March 7, 2019 , 10:20 am

    Does Strontium citrate have the same side effects as Strontium ranelate?
    I had blood clots in my leg as a result of taking hormone replacement a few years ago,

  19. Jenna AlgaeCal

    March 13, 2019 , 3:08 pm

    Great question, Holly! Unlike strontium ranelate which is a prescription medication, strontium citrate is completely natural and clinically supported to have no side effects. You can learn more about the forms of strontium here.

    Give us a call at 1-800-820-0184 if you have any questions. 🙂

    – Jenna @ AlgaeCal

  20. Jennifer Schneider

    April 20, 2019 , 5:36 pm

    Does strontium affect DEXA scan results? I’ve heard that it makes the bone density look greater than it really is, thereby exaggerating the bone’s density. Please clarify!

  21. Jenna AlgaeCal

    April 22, 2019 , 2:27 pm

    Glad you reached out, Jennifer!

    This is a common misconception associated with strontium and we’re happy to share with you the latest research in an in-depth blog post here (scroll down to Myth #3 to learn more, including links to the supporting studies).

    – Jenna @ AlgaeCal

  22. Gwen carter

    August 27, 2019 , 7:22 am

    I was taking strontium and alga plus but after a couple of years I reach out and was told to stop taking the strontium but continue to take the Algae plus I have now had 8 spinal fractures but my lastest scan showed a slight increase in bone density, I now take osteo care which is a calcuim tablet and also my Algae plus am I doing the right thing? Also I have been told that magnesium is now better for you that calcium so getting a bit confused as to what to take.

  23. Megan AlgaeCal

    August 27, 2019 , 12:58 pm

    Hi Gwen, thanks for checking in!

    We’re so glad to hear that you saw an increase in your last scan – any increase at all is incredible since after the age of 40 we naturally lose about 1% of bone density each year. Both calcium and magnesium are important for bone health, and AlgaeCal Plus provides you with the body’s preferred 2:1 ratio of calcium to magnesium. If you are taking the full dose (4 capsules) of AlgaeCal Plus along with a balanced diet, you wouldn’t need to take any additional calcium or magnesium.

    Hope this is helpful, Gwen! If you have any other questions, our Bone Health Consultants are very knowledgeable and more than happy to chat with you. You can reach them at 1-800-820-0184 ?

    -Megan @ AlgaeCal

  24. Elaine Nicastro

    September 27, 2020 , 7:37 pm

    I have been on your Algae Cal regiment of two Algae Cal Plus in the morning and evening and before sleep two strontium boost for 7 years….never breaking this regiment. Recently two stress fractures have occurred in the metatarsal of my foot while walking. Also I have a sever itch on my scalp, face, ears and neck. I have seen many doctors and have multiple allergy tests with allergies. I just read that strontium can cause an itchy reaction…..should I take a break from strontium?

  25. Megan AlgaeCal

    September 29, 2020 , 9:48 am

    We’re so sorry to hear you experienced this while taking our products, Elaine!

    We guarantee our products and definitely want to make sure you are feeling 100%. Have you had a chance to reach out to our Bone Health Consultants yet? They would love to work with you to figure out the cause of what you’re experiencing and support you going forward. If this is something you’re open to, please email [email protected] or call 1-800-820-0184.

    We look forward to hearing from you and helping you along your bone health journey, Elaine. ❤️

    -Megan @ AlgaeCal

  26. Jill Smit

    November 9, 2020 , 11:51 am

    I took your bone building program, but had to back off from 4 /2 pills a day to 2/1 because I had real digestive issues. Now I have developed a blockage in a lesser artery in a kidney. My Dr suggested I drop the strontium because of kidney issue. I have osteoporosis and am a 67 year old female. What can I tell my Dr about the strontium?

  27. Megan AlgaeCal

    November 10, 2020 , 3:22 pm

    Hi Jill, we’re so sorry to hear you experienced this while taking our products.

    We suggest following your doctor’s advice regarding strontium if you have compromised kidney function. Strontium is eliminated by our kidneys, so it may accumulate in patients with chronic kidney disease, as their ability to filter the blood is compromised.

    Regarding your digestive issues, our team would love to work with you to figure out what might be going on. If this is something you’re open to, please contact our Bone Health Consultants at [email protected] or 1-800-820-0184 (USA & Canada toll-free). We’re here to support you throughout your bone health journey, Jill! ❤️

    -Megan @ AlgaeCal

  28. Ben Thomas

    August 8, 2021 , 2:28 pm

    I ordered algaecal plus with the strontium boost.

    For some reason, no matter how easy I go, I can not tolerate the algae cal pill at all. The strontium pills do not upset me. I am therefore taking solgars ultimate bone supplement as this doesn’t effect my digestive system and cause issues. Is it safe to take this with strontium? Sorry to ask about another product but I’m at the end of the road with it all.

    I’m 39 with a -3.9 spinal score ?

  29. Blaire AlgaeCal

    August 10, 2021 , 2:21 pm

    Hi Ben,

    Thanks for reaching out! We’re so sorry to hear that AlgaeCal Plus did not work out for you; however, it’s great you found a supplement that doesn’t disrupt your digestive system.

    Absolutely, you can take it with Strontium Boost. That said, please take it at least 2 hours away from each other.

    Hope that helps! Let us know if you have any other questions 🙂

    – Blaire @ AlgaeCal

  30. Jan

    March 12, 2023 , 8:59 am

    I just read a review of 3 case studies of women who took strontium citrate for a few years. A year after they stopped taking it, the bmd dropped to below initial levels from before they had started supplementing with it. The summation was that strontium was replacing the calcium and giving the effect of bone mineral growth on scans, when it was simply the strontium settling on the bones, and because it has a larger atomic weight, it gives the illusion on scans of building bone.
    On the other side, on your documentation, I see a recommendation to stop taking it after about 3 years. Would the shorter time contribute more to actual bone growth to occur, and would it be better to take a lower dosage of strontium citrate to assure a better overall true bone building result?

  31. Yoori AlgaeCal

    March 13, 2023 , 8:50 pm

    Thank you for sharing your concern with us, Jan! I’m happy to address this for you right away!

    When it comes to your concerns, you are correct in saying that strontium actually can affect results because strontium atoms are heavier than calcium atoms and therefore can have a slight skew in DEXA scans. Research shows that strontium may overestimate DEXA scan bone results anywhere from 8.5%- 11.2% maximum – depending upon the type of DEXA scan machine used. This means if you were to see an increase of 10% between your before and after DEXA scans, the actual adjusted increase may be around 9% (adjusted 10% less of the overall 10% increase). The bottom line is that strontium would never actually lead to a false increase on a DEXA scan, and if you have any further questions about this, please let us know! As well, THIS page on our website addressed this more thoroughly! 🙂

    To confirm, we recommend continuing with the full dosage of Strontium Boost, not only for 3 years, but until you reach the normal bone density in ALL areas measured on your DEXA scan. At this point, you can just take the AlgaeCal Plus for maintenance. You see, AlgaeCal on its own is clinically supported to increase bone density by an average of 1.3% per year. However, we naturally lose around 1% of our bone density per year after the age of 40, and sometimes more depending on other factors like hormonal changes, genetics, lifestyle, etc. AlgaeCal alone is not always able to overcome this accelerated bone loss, which is why we recommend Strontium Boost – because it tripled the rate of bone building in our studies HERE!

    I hope this helps, Jan :). If you have any further questions or concerns, please give us a call at 1-800-820-0184 for more information!

    – Yoori @ AlgaeCal

  32. Betty Springen

    March 11, 2024 , 9:33 am

    I have read that strontium citrate should not be taken by patients who are currently on Prolia. If I would have known that I would have purchased it. I feel Algaecal should make a statement on the bottle, “not recommended for patients on Prolia as well as alendronate, risedronate, zoledronate, or denosumab.

  33. Yoori AlgaeCal

    March 11, 2024 , 3:25 pm

    Thank you for sharing your concern, Betty! We are not aware of any interactions between bone injections or medications, and both our AlgaeCal Plus and Strontium Boost. Please confirm this with a doctor. HERE is our Doctor Information Sheet for your convenience :). I hope this helps!

    – Yoori

This article features advice from our industry experts to give you the best possible info through cutting-edge research.

Lara Pizzorno
MDiv, MA, LMT - Best-selling author of Healthy Bones Healthy You! and Your Bones; Editor of Longevity Medicine Review, and Senior Medical Editor for Integrative Medicine Advisors.,
Dr. Liz Lipski
PhD, CNS, FACN, IFMP, BCHN, LDN - Professor and Director of Academic Development, Nutrition programs in Clinical Nutrition at Maryland University of Integrative Health.,
Dr. Loren Fishman
MD, B.Phil.,(oxon.) - Medical Director of Manhattan Physical Medicine & Rehabilitation and Founder of the Yoga Injury Prevention Website.,
Prof. Didier Hans
PHD, MBA - Head of Research & Development Center of Bone Diseases, Lausanne University Hospital CHUV, Switzerland,