Strontium Ranelate vs Strontium Citrate

Research / January 10, 2012

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. People who consume organic and farm produce usually get enough of this mineral and do not require Strontium supplements. In it’s natural state Strontium is a stable metal element of alkaline nature (atomic weight 38). It is non toxic and non-radioactive. It’s 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 like those with compounds alendronate etc.

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;


Rita Smith

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


Is Strontium boost safe to take if you have epilepsy?


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


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.

ray hendle

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.

ray hendle

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

Eliot W. Collins

Can taking strontium citrate cause kidney stones?


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 from AlgaeCal

Eliot W. Collins

Thanks Monica.

Dr. Sickels

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.

Lara Pizzorno

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.


Hi I have recently been diagnosed with osteoporosis, I am 69, I also have had lymphocytic colitis for nearly 4 years which means That I don’t know what is being absorbed. I am also dairy free.
My doctor offered me bisphosphonates but I prefer to take strontium citrate.
I can get this online as it is not available in the UK. However I am just concerned in reading the above , that if there is a possible problem with availability / absorption of calcium etc , strontium citrate cold interfere with Normal bone development and could possibly result in rickets .
Please could you shed any more light on this . Thank you .


Hi Sue,

That’s a great question. Calcium and strontium citrate compete at the same sites for absorption because they are two chemically similar minerals. In other words, if you take them at the same time of day, yes, it will be an issue as calcium will always win. (Meaning it will out-compete strontium and reduce its bio-availability). BUT, this is an easy fix. You
simply just take them at separate times throughout the day.

You can take your AlgaeCal Plus (calcium supplement) with breakfast or lunch and then take your Strontium Boost (strontium citrate) at night before bed. Strontium supplements need to be taken along with adequate calcium consumption. (Studies suggest strontium is not effective and may even be counterproductive if your calcium intake is not normal) Also, taking AlgaeCal Plus and Strontium Boost together (but not during the same time of day) have been proven with clinical trials to INCREASE bone density, naturally. You can view this study here:

The following are some great resources on calcium and strontium citrate, too:

Hope I have shed more light on this for you, Sue.

– Monica from AlgaeCal


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!


Hi, I stopped taking a calcium supplement some time ago as apparently it interferes with absorption of Oroxine (thyroxine) that I take. I have now been diagnosed with osteoporosis after a recent fracture. Wondering your thoughts on taking AlgaeCal Plus and Strontium Boost in combination with Oroxine? Thanks


Hi Ray,
As a general rule of thumb please take all medication separately from other supplements and medications unless directed by a physician. Thyroid medication is known to interact with calcium rich foods/ supplements therefore, we recommend 4 hours apart to prevent any possible interaction!

Many of our customers on AlgaeCal’s Bone Builder Program (AlgaeCal Plus and Strontium Boost) take their thyroid medication first thing in the morning and take their AlgaeCal Plus at lunch and dinner. Then Strontium at bed time with water on an empty stomach.

If you’d like to call in and discuss your bone health more in-depth with one of our Bone Health Advisors, you can call USA and Canada toll free at 1-800-820-0184 Monday through Friday: 6am to 4pm (PST) and Saturday & Sunday: 8am to 2pm (PST).

– Monica @ AlgaeCal


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


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.

Lara Pizzorno

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

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