A letter from a chemist to homeopaths

Dear Homeopaths,

Homeopathy awareness week is here again. And I’ve got some questions about this most popular of alternative therapies. The answers to which I’d very much like to be aware of.

Homeopathy, as I understand it (please correct me if I’m wrong), is based on a idea that ‘like cures like’. So if your hayfever causes runny eyes then onions may be be able to help (because onions cause similar symptoms). Or maybe you suffer from insomnia, in which case caffeine may be the solution. However a cup of strong coffee is likely to keep you wide awake. So you get around this through massive dilutions. This way, you claim, the beneficial effects are retained whilst the unpleasant side-effects are removed. 

Now before we go any further let’s make sure I understand the dilution process, again using the caffeine example. You might start with a solution of caffeine that’s about the same concentration as coffee. Then you perform a 1 in 100 dilution. The solution is shaken, often by hitting it against a leather bound surface (a process known as succussion). The result is known as a 1C solution. You perform another dilution, shake etc. resulting in a 2C solution. The process continues often 30 or more times. The net result is a solution that will not contain a single molecule of the original. In fact it might be the equivalent of diluting the cup of coffee in sphere of water the size of the solar system.

So far I hope we can agree. But it seems rather unlikely, to me, that this process might result in an effective remedy. Although you have explanations e.g. ‘water is capable of storing information relating to substances with which it has previously been in contact’. Or to put it another way the water can remember what was diluted in it.

There is no sound scientific evidence that water has any such memory storage capacity. However, homeopaths often tell scientist that we should be more open minded and not to be so wedded to the dogma that we have been taught. So here I am, putting my education and experience in chemistry to one side for a moment.

Nevertheless, even without everything that chemistry might tell me, I’m still left with what seems to be some logical holes in your therapy.  Hence my questions for you, and I really am interested in the answers.

How come the water remembers the starting substance (e.g. the caffeine) but not impurities?

The gold standard for water purity (used by analytical chemists, but not homeopaths) is just 10 parts impurity to 1 billion parts water. The concentration of these impurities is equivalent to a 4C solution. So in dilutions made beyond this point the impurities will outnumber the original substance. How then can the homeopathic solution know which molecules it is supposed to store information about?

How do you make an oxygen based homeopathic remedy?

There appear to be quite a few remedies based on oxygen. But oxygen from the air will continually dissolve in the water you use to dilute your solutions. So how do you actually manage to make a 30C dilution of oxygen, when at every step along the way you are just adding more of it to your remedy?  

How is the power of a remedy transferred from water to a dry pill?

You make pills by dropping a water remedy onto a sugar tablet and then drying it. How is the stored information (supposedly in the water) retained in the pill after the water has evaporated?

Why can’t I find a homeopathic contraceptive?

I looked and you don’t seem to make or sell any.

If the potency of a remedy increases the more it gets diluted why can this never be perceived as a strong taste?

If a remedy is to work then it must interact with our biology. Why does this never manifest to our sense of taste?

Why was homeopathy so ineffectual at combating infectious diseases before the advent of vaccines?

Your theme for this years homeopathy awareness week is infectious disease. Vaccinations have reduced the spread of infectious diseases to a tiny fraction of what they once were. Homeopathy was around long before most vaccinations were commonplace, so why did it fail to reduce the incidents of infectious diseases?

I hope by answering these you might be able to give me a greater awareness of how you believe your therapies work.

Yours sincerely,

Dr Mark Lorch

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  1. That’s one of the best article on homeopathy I’ve ever read. Thank you very much!

  2. It is sometimes exceedingly difficult to counter misinformation from those who believe in pseudoscience (e.g. the anti-vaccine crowd or climate change deniers) as studies have shown that providing them evidence that they’re wrong actually strengthens their views instead of changing them. Vox published an interesting piece today discussing the ethics of how to cover such views (e.g. might covering them, even in a negative way, give them more exposure and more influence?).

    • You are never going to convert the die hard believers, its like arguing with a religion. But you may manage to inform some who are border line.

  3. I’m also a chemist. I totally agree with your view about homeopathy (i deduced your view from your ironic questions). I now leave in France, where some homeopathic drugs are prescribed by physicians. Last month, the physician of my wife gived here hometopathic drugs to take. I had to keep my mouth with both my hand to not make any comment in the cabinet, and later at home. I did say a word because one thing homeopathic drugs are good is placebo effect. If i had say my opinion, i would have ruined this effects for my wife. You know that for some trouble, placebo can releaf 30% of symtoms. I think that as scientist, we must be aware of the bad usage of homeophatic, but without doing to much.

    • Hi Serge,
      I agree, the placebo effect can be extremely strong. And practitioners of alternative therapy can be extremely good at maximising its effect. In that respect I think medicine has something to learn from homeopaths and the like.

      • Speaking as a doctor, we are very aware of the placebo effect but are limited in its use of the by the ethical requirement to discuss how a medication works and what risks and benefits are associated with its use. This process dilutes the placebo effect, which definitely does not make it more potent.

        • Sorry, I should clarify what I mean. I’m not suggesting medics should knowingly prescribe placebos.

          What I meant is that the placebo effect seems to be particularly powerful when accompanied by a good bedside manner and health practitioners who have the time to spend with the patient. In that respect some alternative therapist (because they are being paid by the patient) may be able to spend more quality time with a patient that an over worked nurse or doctor. And the result is a stronger placebo effect.

  4. If homeopathy works, why aren’t we all dead of poison overdoses?

  5. Oh, I think I can answer the one about the homeopathic contraceptive. Obviously, since like cures like, a homeopathic contraceptive would have to be made of ground-up babies.

    So I’m guessing that there was a bit of an ethical problem there.

    Anyway, looking forward to hearing the homeopaths answer the others. Especially the one about how the water memory works after the water has evaporated.

  6. From my encounters with homeopaths they give answers to these questions in the form of: “Because energy”, or “Quantum water memory” or “Love is the basis of the Universe and that’s how the water knows which chemical to remember” or other pseudo-scientific arguments. In other words, they cannot afford to have intellectual honesty, because that would mean that they should abandon their homeopathic views which are obviously very comforting for them (either through habits of thought, or actual reinforcement from the surroundings – some make money, other join groups and feel a sense of belonging, others are very sick and need to hold on to a delusional idea, etc.). It also means that they have to spend extra energy to understand real science, which is a painful process if you are brought up to believe in bullshit. The solution as I see it would be to educate children in science and to think critically for themselves from an early age.

  7. All very good questions. But homeopaths would only be interested in discussing these if they actually *cared* whether homeopathy really worked. From all I’ve seen, they don’t care at all, they just believe. You might as well try to discuss geology with Ken Ham.

    • You are quite right. This is the sort of response I’ve had.

      Which I think translates as
      “with skeptics if they have questions seeking information , We have much work and is published .”

      So I guess we can just replace the world ‘skeptics’ with ‘homeopaths’ and throw it right back.

  8. Mark, thank you for writing this. Several of your questions are better than any which I have written. This blog will be added to my reference materials.

    It is disturbing to contemplate the abjectly oblivious beliefs, or the knowing & willing acceptance of ideology, which allows so many to accept massive amounts of homeopathic preparations of poop – dog, fish, bird, human, bacterial, et al. poop.

  9. Just one remark on this: homeopathic drugs can cause side-effects just as conventional drugs do! So if a person who never read the prescription-paper and just followed the doc´s instructions on taking the homeopathic drug gets side effects visible on the skin or something like that… how would you explain that? sugar allergies?

  10. What you believe what you take does can have a strong effect on your physiology whether it’s a positive placebo or a negative nocebo effect.


  11. I always wonder when homeopathic water stops remembering all the other things it has been in contact with in the past.

  12. If I dissolve 150 mg of MDMA in a glass of water (250 ml) and make a 20C solution will I die of MDMA overdose? No! Why then does it supposedly work with medicines.

    • It’s actually been a poor student practice of mine for many years, watering down the keg to one jug of beer and 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 litres of water,so that I can get people drunk on the cheap (some argue this is a negative effect of the chemical alcohol that we should be attempting to eliminate; I on the other hand ‘believe’ that intoxication is the positive medicinal effect that I am attempting to spread).

      I have been considering engaging in a similar practice with THC oil… but I don’t really want to get done for distribution of narcotics.

      And now, the news at 6: woman decides to have baby, flushes contraceptive pills down the toilet, and puts the world’s marine population into a mass extinction effect.

  13. I would ask; why do you need to buy another dose when your bottle is nearly empty? Wouldn’t the next dose be even stronger if you just topped the bottle up with water yourself?

  14. I think the reason there are no homeopathic contraceptives is because nobody wants to drink water with sperm in it, no matter how diluted it is.

    But yeah, great points highlighted. I think another point is not just the impurities but the type of impurities. When you think about where every molecule of water has been around the earth shouldn’t we be technically immortal & never get sick? When contaminated water is dumped in the ocean shouldn’t that make the fish thrive, not kill them? And why doe’s it only work bad stuff? If I eat or drink anything with vitamin C that’s been diluted, like orange juice, then shouldn’t I get scurvy?

    There are so many questions this can bring up. I actually think this would make a good exercise in critical thinking for chem students to help them with designing experiments.

    • Hey Mitch, you realise that your tap water is already highly diluted semen, right?
      Hey…. Maybe that’s why the birth rate is falling!

  15. Terry Keating says:

    “So in dilutions made beyond this point the impurities will outnumber the original substance.”
    You might want to clarify that by explaining that the impurities will remain 10 ppb through all successive dilutions, but the substance will continue to decrease to nothing.
    I don’t think that will be obvious to everyone.
    Otherwise, great work and very readable, Science Babe.

  16. This was a very dangerous article I was taking a drink of Pepsi Max when I got to the paragraph that starts “Why can’t I find a homeopathic contraceptive.” and when I laughed the Pepsi came out my nose. Dr. Lorch should have anticipated that happening. Oh, well, I’ll survive, so forgive and forget.

  17. another frustrating thing is in this attempt to question and educate people about homeopathy is how the industry has blurred the line between it and herbal remedies. i had an debate with a fella who was using the whole ‘it works because i used it under uncontrolled conditions and i just know it was what made the difference’ line and when i started the asking questions aproach like this article did I discover that what he was doing was just making a self-harvested herbal tea, which isn’t homeopathy at all but some ‘wellness’ fair person was telling him was just like how she was making her homeopathic remedies.

  18. According to an old biology professor of mine, the seeds of queen Ann’s lace have some contraceptive effect and was used by native Americans.

    • This would be naturopathy, not homeopathy. There are a number of “natural” remedies (plants, extracts, etc.) that can interfere with hormone uptake thereby interfering with pregnancy, or decrease blood clotting thereby increasing the likelihood of bleeding and miscarriage. Unfortunately, it is not an exact science and therefore not reliable.

  19. “The net result is a solution that will not contain a single molecule of the original.”

    I agree with the sentiment and the purpose of this entire entry, however, if you have a gram of caffeine, you can add water to it all you want, the caffeine will still be present within the water to some degree unless its been otherwise modified, separated or decomposed by some other process.

    A cup of coffee distributed throughout the solar system does not mean there is no coffee present throughout the solar system, even if its just one drop per astronomical unit, its there.

    Just being a nitpick.

  20. @Kevin this isn’t just a matter of dumping a cup of coffee in a swimming pool. Not to labour the point, but-

    Say you have 1g caffeine in 100ml water = 10mg/ml.
    Take 1ml of this, add to 99ml water = 0.1mg/ml (1C dilution)
    Take 1ml of this, add to 99ml water = 1ug/ml (2C dilution)
    Take 1ml of this, add to 99ml water = 10ng/ml (3C dilution)
    Take 1ml of this, add to 99ml water = 0.1ng/ml (4C dilution)
    Take 1ml of this, add to 99ml water = 1pg/ml (5C dilution)

  21. Dr Lorch,

    So, I’ve thought about this a little and based on what I understand, we shouldn’t need to dilute anything in water since water is very old. By that notion, it’s come in contact with pretty much everything that exists on this planet. So it should already have the memory of everything it’s every touched, and it should be incredibly strong as a remedy since it’s incredibly diluted, if you consider the entire water source as a whole.

    So, in other words, we would only need to drink tap water since it’s very old and has been in contact with everything that exists on this planet. Right?

    If that notion is true, why do diseases still exist? Why do people still get headaches?

    Or is there a point that the water starts to forget?

    How does it know to target only the good parts?

    Are there any examples of homeopathy curing HIV?


  22. I think the answer to the birth control question is very simple and obvious – everyone using homeopathic birth control would continue to get pregnant, therefore providing widespread and definitive proof that homeopathy does not work.

  23. Allow me to suggest a payment method for patients of Homeopathic medicine:
    When you are billed for the homeopathic service (let’s say the bill is $100), dilute that amount tenfold.
    Repeat thrice.

    Send the penny as payment, with an explanation that the penny still retains the buying power of the original $100.

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  25. Anonymous Physicist says:

    I can’t help but notice the people who agree with homeopathy and other forms of pseudoscience have the scientific literacy and education of an 8-year old. Surely this must just be coincidence?

    Never mind how much intensive work and learning and thinking goes into learning a real science (like physics, chemistry, biology), let’s just ignore all of that because it’s simply too difficult for our brains to understand. I’m taking the side of diluted chemicals in water having benefits directly contradictory to all known and proven science, because it’s simply easier to believe that than it is to think and learn about actual reality.

  26. Thank you for explaining the rationale and chemistry behind homeopathy versus actual scientific solutions such as vaccinations. Excellent information.

  27. Just a quick and easy question, Mark. You state “However a cup of strong coffee is likely to keep you wide awake.” What about the side- or aftereffects of coffee? What kind of reaction does the action of coffe produce?

  28. According to the Caffeine Pharmacology http://www.news-medical.net/health/Caffeine-Pharmacology.aspx effects from coffee may include sleep deprivation and sleeplessness, and sideeffects or withdrawal symptoms may include sleepiness. Doesn’t that bring out the possibilty of insomnia being cured by the correct use of and the best adjusted dose of caffeine – in the sense of sleepiness occuring when the effect of the caffeine expires?

    • So let me make sure I have understood your argument.

      You are suggesting that because withdrawal symptoms of caffeine can lead to sleepiness, therefore administering caffeine could be used to treat insomnia. Correct?

      • If one of the primary effects (action) of caffeine is sleeplessness and one of the secondary effects (reaction) is sleepiness, as suggested in the Pharmacology – yes.

        • But its the lack of caffeine that causes sleepiness. And even then you might feel sleepy but still suffer from insomnia.

          If stopped abruptly, caffeine may also give rise to withdrawal symptoms. Examples of these include:

          Loss of concentration
          Sleepiness in presence of insomnia

          • You’re right about the insomnia still present. That’s a more precise observation. What you call lack of caffeine I would call a reaction of the action of caffeine (like in Newton’s 3rd law), because this spesific state would not exist without the intake of caffeine in the first place – but I’ll leave it this way right now.

  29. When I was young homeopaths were these lovely, slightly scatty middle age ladies that treated their family’s minor colds and coughs that sort of thing. The dawn of the internet (or stupid-spreader as some call it) saw much more vociferous advocates becoming more and more aggressively convinced of homeopathy’s worth, simultaneously (under pressure of open questioning) making the whole ‘science’ more and more elaborate, making wilder and wilder claims.

    My question is: What happens to this new movement of internet psyched-up neo-homeopaths start getting on a bit and start getting age-related illnesses that need proper medical treatment (diabetes, Parkinsons, cancer, blood-pressure issues, that sort of thing)? It could be like watching a car crash in slow motion seeing them doggedly refusing conventional medicine whilst all the time blogging their daily experience on homeopathy.

    What happens if for instance Dana Ullman gets pancreatic cancer? He’d surely fell duty bound to treat himself with an elaborate concoction of 30C this 1M that whilst publicly charting his progress with the disease on the internet. It would make for terrible reading, even for the most ardent homeopathy critic.

  30. Hi Mark,

    I’m a Homeopath and I also have a chemistry background.

    I guess the simplest way to look at the issue is to see how a pharmacist would explain the ” Placebo ” effect.
    I believe they say it is in the mind.
    I would then ask why a ” thought “, which is not a solid, liquid or gas, can be believed to have a physical effect on the body? How many milligrams or micrograms of ” thought ” does it take to develop symptoms?

    Conventional medicine accepts the placebo effect, but by accepting it, they contradict their own principles by which they criticise Homeopathy.

    So I believe an understanding of the placebo will automatically aid in the understanding of how Homeopathy works.

    • Hi Ash,
      Not quire sure what you are getting at. Are you saying that the bases of homeopathy’s effects lies in the placebo effect?

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  38. such an informative article
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  39. such a helpful blog
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  40. Great post! Thank you for sharing these information. It is really useful for me.

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