Why statin side effects are likely to be much more common than official statistics suggest

In the UK, the most popular ‘drugs bible’ goes by the name of the British National Formulary (BNF). Within its pages is found a wealth of information about pills and potions that are available over-the-counter and by prescription, including indications and advice of dosages. A significant proportion of the pages in the BNF are taken up with information about contraindications (situations where the drug should be avoided or used with caution) and side-effects. This information is now to be found as part of the packet insert which comes with medication. I’ve known many, many people to read this information and decide that they’ll give the medication a miss.

One class of medication with a range of known side-effects are the statins. These cholesterol-reducing drugs are known to have the potential to cause symptoms such as muscle pain and fatigue, as well as cause damage to organs such as the liver and kidneys. About a year ago I was at a medical lecture, and one (doctor) member of the audience commented that he felt his patients experienced side effects from taking statins far more commonly than official statistics suggested. My own experience supports this observation.
Could there be an explanation for this phenomenon?

One explanation has to do with the design of statin studies. Quite often, individuals who are in poor health and perhaps at increased risk of side-effects are automatically barred from entering a study. Yet, in the real world, even people who are poor candidates in this respect may end up being prescribed a statin. Individuals with a history of problems such as muscular pain or damage to the liver or kidneys (all of which can be exacerbated by statins) are typically excluded from studies too, further reducing the chance that side-effects will arise.

Even those who make it through this screening process, however, may be subjected to what is known as an ‘run in’ period prior to the study. Here, individuals may be treated with a statin with idea being that individuals who are ‘non-compliant’ (do not take their medication as instructed) are weeded out. However, the run-in period also affords the researchers the opportunity to detect individuals who are susceptible to statin side-effects and stop them getting into the study proper.

In other words, in formal studies participants are often at a significantly lower risk of side-effects than those in the general population.

Another problem with conventional studies is how side-effects are defined. Muscle pain is a quite-frequent side-effect of statins. In extreme cases, statins can cause a break-down of muscle tissue known as ‘rhabdomyolysis’ which can have potentially fatal consequences. In some studies, the focus has been on rhabdomyolysis, which means less severe side-effects such as muscle pain or fatigue may ‘go missing’.

Another way in which the bar for side-effects can be set very high concerns the blood parameters used to detect damage. For instance, in a recent study muscle damage was only deemed to have occurred when muscle enzyme levels (a marker for muscle damage) were at least 5 times the upper limit of normal [1]. In this same study, liver damage (another potential hazard of statins) was only deemed to have occurred when liver enzymes were at least 3 times the upper limit of normal. In both cases, a more logical approach would be to regard a rise of any amount above the top end of the normal range as abnormal and significant. This would be more how it is in actual clinical practice.

The elimination of individuals prone to side-effects and the setting of the bar very high for abnormalities help explain why the side-effects from statins seem much more common in the real world than officially quoted statistics.

However, even in the real world, there might be under-recognition of the damage statins can do. That’s because, quite often, doctors will dismiss the idea that statins might be the cause for someone’s symptoms, even when scientific evidence supports such as link. For more on this, see here.


1. Nicholls S, et al. Effect of Two Intensive Statin Regimens on Progression of Coronary Disease. NEJM 2011;365(22):2078-87

11 Responses to Why statin side effects are likely to be much more common than official statistics suggest

  1. Morwenna Given 13 April 2012 at 5:32 pm #

    As a practising Medical Herbalist in Toronto Canada I totally endorse the high level of side effects patients experience with statins. One of the major problems I believe are that conventional doctors do not understand the biochemical mechanism of statins and consequent damage and thus do not look for symptoms – obliged to prescribe by mandated protocols and with no other drugs to mediate cholesterol ( if required ) they follow the rule book with inadequate professional performance and thought applied. I personally feel that we will have an upsurge of auto immune disease due to this drug. Having taken an extensive case history of a patient of mine who is now considered to have ALS / Lou Gehrigs disease I realised he had been on an artificially low level of cholesterol for 10-15 yrs and told him in my opinion this was the cause of his ALS due to suppression of the immune system and invasion of the myelin sheath altering neuronal signalling.
    Last month after 2 years with the orthodox specialists his neuro surgeon confirmed my initial diagnosis.

  2. Feona 13 April 2012 at 7:10 pm #

    I took just one Lipitor some years ago and woke up in the middle of the night with pins and needles going up both arms, up my neck and across my lower jaw. Next morning, I felt as if someone had punched me heavily on the right shoulder. Never taken another statin and I never shall. Anyway, I’m a woman, over 50, with no history of heart problems. Why the hell did my consultant prescribe statins for me in the first place? I haven’t seen him since and, frankly, I have no idea of my cholesteol levels, nor do I care. If this reads as stroppy, that’s because I’m angry that someone who is supposed to be an expert should take such a unnecessary risk with my health.

  3. Kay 13 April 2012 at 8:03 pm #

    I stopped taking statins when the muscles in my left arm made it difficult to move it at all

    I had read that muscle damage could be a side effect of statins, so didn’t bother my GP about it – so it could be that in the age of Google there are many more people out there like me, who do their own diagnosing, and so never become a statistic

  4. robert orr 14 April 2012 at 12:30 am #

    I saw my GP today about fatigue and she made no reference to my statin intake – I’ll raise it with her when I phone for my blood results, thank you

  5. Phil 14 April 2012 at 10:58 am #

    I have type 1 diabetes and the pressure to take these drugs from health professionals is relentless. I stopped taking Atorvastatin 2 years ago and almost immediately, muscle pains, leg cramps and severe headaches disappeared. I just hope that for the 10 years that I did take the drug, no long term damage has been caused. Thankfully, my liver and kidney function appear to be fine.

  6. Debbie Axworthy 14 April 2012 at 5:01 pm #

    Dr Briffa – direct question that I am finding difficulty in getting answered. My dad has Gilberts Syndrome and has been advised that his cholesterol levels are high. He has been prescribed statins. His GP advised that that it should not directly affect his liver. Is it usual to prescribe a statin to someone who already suffers with liver detoxification process ?

  7. Morwenna Given 14 April 2012 at 7:23 pm #

    re Debbie Axworthy’s comment. Gilbert’s is a genetic syndrome involving the formation of bilirubin in the liver – normally benign but with anxiety associated symptoms. Statins are contra indicated in this situation because of the interference in the liver caused by neuronal signalling. A detailed biochemical explanation can be found in: The biochemistry of statins involves the inhibition of the redox chain and CoQe10 in the mitochondrial wall in order to inhibit the synthesis of cholesterol. (Structural mechanism for statin inhibition of HMG-CoA reductase.
    Istvan ES, Deisenhofer J. Department of Biochemistry, Howard Hughes Medical
    Institute, University of Texas Southwestern Medical Center at Dallas, TX 75390-9050, USA. Mol Pharmacol. 2009 Jun;75(6):1421-9. Epub 2009 Mar 30.)

    Inhibition of this affects the immune system and the inflammatory cascade i.e. it works to increase the effects of aspirin as well as negatively affecting the liver and pancreas (Statin-induced liver
    injury involves cross-talk between cholesterol and selenoprotein biosynthetic pathways.Kromer A, Moosmann B. Institute for Physiological Chemistry and Pathobiochemistry, Johannes
    Gutenberg University, Mainz, Germany. PLoS Med. 2008 Mar 25;5(3):e64.) to
    cause further impaired metabolism. ( Effect of the magnitude of lipid
    lowering on risk of elevated liver enzymes, rhabdomyolysis, and cancer: insights from large randomized statin trials.Alsheikh-Ali AA, Maddukuri PV, Han H, Karas RH.Molecular Cardiology Research Institute and Division of Cardiology, Department of Medicine, Tufts-New
    England Medical Center and Tufts University School of Medicine, Boston, USA

    Dr Briffa I replied to the question asked as I have Gilbert’s syndrome patients so am more than familiar with these issues – hope you did not find it intrusive.

  8. helen 14 April 2012 at 11:01 pm #

    If you need any more proof as to why you should avoid statins read this essay http://people.csail.mit.edu/seneff/why_statins_dont_really_work.html

  9. Debbie Axworthy 15 April 2012 at 8:11 pm #

    Thanks for this information Morwenna. Thought as much and will definately be reading the suggested reading material.

  10. anthony Kerstein 15 April 2012 at 10:24 pm #

    Dr Briffa:
    Another common side effect, which I experienced, along with muscle pains, is severe memory loss. I thought I was getting dementia until reading The Great Cholesterol Con by Dr Malcolm Kendrick pointed to the real reason. You’re comments on the dangers of too low cholesterol seem right on the nail.

  11. dave chandler 24 April 2012 at 8:46 pm #

    Bit late but I too experienced memory loss.At first I put it down to old age but after stopping statins my memory is a lot better.

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