• Islon Woolf MD

We all self-experiment with our health, but we get it wrong

Updated: Jun 16


In this email I will demonstrate that self-experimentation is necessary for your health. Everyone does it. Unfortunately, most people draw the wrong conclusions from their self-experiments; they conclude a treatment works if they feel better. However, there are many reasons to feel better even when the treatment doesn’t work. Let me explain.



Self-experimentation is necessary, everyone does it

Self-experimentation is an essential part of health. Humans have used it for eons to discover the impact of our environments, habits, foods, and treatments. For instance, think of all the foods on your table. Someone, somewhere in our past, must have self-experimented to determine whether those foods were edible. Fast forward to modern times, the Nobel laureate Barry Marshal drank the bacteria H. Pylori to prove that it causes ulcers.


Self-experimentation is even necessary for well-established treatments - treatments validated by large clinical trials on hundreds of thousands of subjects. This is because clinical trials only prove a treatment works on average in its subjects. No treatment, no matter how established, is 100% effective, or 100% without side effects, in all subjects. Therefore, clinical trials cannot guarantee that you personally will get better. After all, each one of us is physically and biochemically unique. Different people will respond differently to the same treatment. A few notable examples include: anti-depressants, that work in some but not in others, and the muscle building supplement creatine, that doesn’t work in up to 40% of people. Even the same person may respond differently to the same treatment at different times in their life; every time you take penicillin you are experimenting to see whether you have developed an allergy.


Self-experimentation is even necessary for well-established treatments. Clinical trials only prove that the treatment works on the entire group, on average. They cannot guarantee that you personally will get better.

Self-experimentation is used by people in all phases of health and sickness. For instance, healthy young “biohackers” use it to optimize their lives. They play with everything from psychedelics to ambient bedtime lighting just to eke out evan a small performance enhancement. While patients with terminal cancer, and nothing left to lose, self-experiment when conventional therapies fail.


Ultimately, self-experimentation is unavoidable. Any change you make in your life is an exercise in self-experimenting with health. This is because any change has the potential to impact your physical or mental health. A simple change of your job, for instance, may change your feelings of self-worth, socialization, sleep time, activity levels, and even your diet. For better, for worse, or for nothing. The entirety of all these changeable things is called the exposome (see diagram bellow). The exposome is in contrast to your genome, which you are born with and cannot change. The exposome includes anything your body or mind can be exposed to, such as: thousands of food options, thousands of work or social options, hundreds of exercise options, hundreds of relaxation options, thousands of environmental exposures, hundreds of hormone pathways, thousands of supplements and medications, etc. The number of options in the exposome, and their interconnectedness, is infinite. This means that with or without knowing it, you have already conducted thousands of experiments on your health.




The fundamental error of self-experimentation


Despite all the self-experimenting going on, and the importance of self-experimenting, people draw the wrong conclusions from them. In fact, we seem to be hard-wired to make the same fundamental error. An error closely related to the “correlation does not imply causation” error. It goes something like this, “I took Treatment X, I feel better, therefore Treatment X works.” The truth is, there are many reasons to feel better after a treatment, even when the treatment does not work. The following is only a partial list of reasons:

  1. The natural history of the condition: most conditions resolve (acute back pain, respiratory infections), or they wax and wane (fatigue, arthritis, autoimmune disease, insomnia). This makes it quite common to mistaken the natural improvement of a condition for the effect of a treatment.

  2. Regression to mean: we initiate a treatment typically at the peak of symptoms, when we feel the worst. There, the symptoms have no place to go, but improve.

  3. Concurrent treatments: we often employ many treatments at once, especially when we are ill. It’s hard to tell which worked and which did not.

  4. Other exposome changes: in addition to our active treatments, the rest of our exposome is constantly changing with or without our knowledge.

  5. Placebo effects: the mind is easily placated by the thought of a treatment. This makes one “feel” better, without actually affecting the underlying disease.

  6. Subjective outcomes and sloppy measurements: Outcomes such as reduced pain, or increased energy are difficult to measure. Most of us are not meticulous in making these measurements. This permits confirmation bias. If we desire the treatment to work, we selectively emphasize and pay attention to the outcomes it improves, and ignore the outcomes it does not.


Despite being fooled most of the time, I will concede there are certain circumstances where self-experimentation produces more reliable evidence. For example, a new treatment that could prevent a death in an Ebola patient, should not be ignored. This is because the natural history of Ebola is rapid death in 70-80% of patients. However, self-experiments such as this, in diseases as definitive as Ebola, are the exception, not the rule.



The fundamental error is used to validate medical pseudoscience


We are so prone to making the fundamental error that, sadly, even doctors make this error. The COVID pandemic provides us with a more recent example. We all witnessed doctors applying the fundamental error to popularize ineffective treatments. It went something like this, “My patient was sick with COVID, I gave them treatment X, they did not die, therefore treatment X works.” However, unlike Ebola, the natural history of COVID is full recovery in at least 99% of cases. This means, if their patient took nothing, they had a 99% chance of recovery. This is where we get the saying, “Let nature do the healing, and the doctor take the fee.”


We are so prone to making the fundamental error that, sadly, even doctors make this error.

In deed, you will find that whenever you communicate with a quack, no matter how implausible, or how ridiculous their idea, they almost invariably defend it with the fundamental error, “It works because my patient got better”. In this way, the fundamental error can be used, and is used, to validate ANY idea in medicine. And as I have written prior, this is the hallmark of pseudoscience. To only seek, and easily trust, evidence that proves your idea is right. No matter how weak the evidence, or how prone it is to error.

There is only one way to combat pseudoscience, and that’s with science. In my next email I will show you how to self-experiment properly by applying the scientific method.