The placebo effect is a very interesting thing to study. To keep this scientific, though, let's divide your question into three addressable points:
- Does the placebo effect work?
- Does the placebo effect work on you?
- Can the placebo effect be scientifically tested?
If each of these points can be resolved as true, then it would be fair to call the question answered. Also, at the bottom you'll find some suggestions for a placebo self-test.
What is a Placebo, What is the Placebo Effect?
A placebo is a treatment that looks like a regular treatment, but is actually an inactive look-alike, and not a medicine. Placebos are used in medicine to evaluate the effectiveness of treatments, as often some of the benefit from a treatment will actually be due to the placebo effect. In a controlled trial, some trial subjects are given the treatment being tested, and some are given placebos. Ideally, the subjects can't tell the difference, and at the end of the study, the effectiveness of the drug can be compared to that of the placebo.1
In practice, this often means sugar or cornstarch pills, but can extend to other treatments as well. In fact, even surgical procedures can be placebos. Known as sham surgeries, surgical placebos often involve the administration of anesthesia followed by several incisions similar to those that would be made during typical surgery.2
What is the placebo effect that makes all of this necessary? The placebo effect is the improvement in a medical condition resulting from the belief that one is being treated, rather than the effectiveness of the treatment itself.3 Because patients tend to believe they are being given an effective treatment, this belief itself contributes to improvement in condition.4
Does the Placebo Effect Work?
A number of examples can be used to demonstrate the effectiveness of the placebo effect. Several of them conclude that not only is the placebo effect powerful, it is sometimes more powerful than the medication alternatives.5
A migraine study conducted in 2014 compared the effect of the migraine treatment rizatriptan (sold by Merck Pharmaceuticals as Maxalt) to a placebo, by administering envelopes with drugs in them to migraine sufferers. The subjects were instructed to take the medication in case of migraine. The envelopes came in pairs labeled 'Placebo', 'Maxalt' or 'Placebo or Maxalt', however, each pair actually had one placebo envelope and one Maxalt envelope. Yet, subjects reported the same level of pain relief from placebo labeled Maxalt as from Maxalt labeled placebo, suggesting that placebos are sometimes as effective as actual medication. Patients also reported pain relief from the placebo labeled placebo, suggesting that even one who knowingly takes a placebo can still be subject to the effect.6
A study specifically designed to evaluate the placebo effect compared fake acupuncture to fake pills, a comparison of two placebos. Subjects suffering from arm pain were either prescribed acupuncture or pain medication, but the pain medication was cornstarch pills, and the acupuncture used needles with tips that retract into themselves upon touching skin, like stage knives. The subjects were warned about possible side effects of the treatment, with the side effects mentioned taken from actual side effects of either real treatment. Interestingly, one third of patients reported the exact side effects they were warned about, including excessive drowsiness in the pill group, and redness and inflammation in the acupuncture group, even though the skin wasn't actually pierced. Some patients in both groups reported extreme pain, but more interestingly, most of the subjects reported extreme pain relief.7
Does the Placebo Effect Work on You?
An effective method of proving widespread viability of the placebo effect is showcasing its virality, quite literally. When one believes he is sick, and starts developing actual symptoms as a result, the medical community refers to this condition as 'psychogenic illness,' or actual illness spawned from the belief of illness. When this believed illness is believed to be contagious, anyone who hears about it can himself become ill, experiencing the full range of purported symptoms. This is known as 'sociogenic illness', and it is potentially the most infectious category of illness in existence. This is because it "infects" through information, making mass media often the single greatest transmission vector. Most worryingly, the current medical opinion is that there is no particular predisposition to mass sociogenic illness and it is a behavioral condition that anyone can show in the right circumstances.8
A 2006 study testing individual sensitivity to GSM cellphone signals found no evidence that people with self-reported sensitivity to mobile phone signals are able to detect such signals or that they react to them with increased symptom severity. As sham exposure was sufficient to trigger severe symptoms in some participants, this condition was most likely sociogenic illness.9
A 2012 study testing whether media coverage of people sensitive to WiFi signal contributed to reports of WiFi sensitivity concluded that media reports about the adverse effects of supposedly hazardous substances can increase the likelihood of experiencing symptoms following sham exposure and developing an apparent sensitivity to it.10
A case study about mass illness attributed to toxic exposure at a high school had features of mass psychogenic illness. Notably, widespread subjective symptoms thought to be associated with environmental exposure to a toxic substance persisted in the absence of objective evidence of an environmental cause.11
In other words, sociogenic and psychogenic illness exist, there is no particular predisposition to mass sociogenic illness and it is a behavioral condition that anyone can show in the right circumstances.12
Can the Placebo Effect be Scientifically Tested?
All of the previous studies seem to indicate that yes, the placebo effect can be scientifically tested, but as a final confirmation, a study conducted on subjects with Alzheimer's disease showed that these subjects got less pain relief from pain medications. They required higher doses, possibly because they had forgotten that they were getting the drugs, or they forgot that the pain medicines had worked for them before.13
In other words, Alzheimer's disease seems to allow the comparison of placebo effect and the lack thereof. Because Alzheimer's disease patients do not remember taking their medication, they receive far less benefit from it due to the lost contributions from the placebo effect.
A Suggestion of Methods
Now that we've scientifically proven that the placebo effect works, it is powerful, and it by all means should work for you, even if you know you are or may be taking a placebo, we may devise some methods.
You will likely need an external source of entropy, and should most likely not use a placebo in place of actual necessary treatment. This would mean that you will want a medication that does not cure any particular disease, though maybe alleviating symptoms is a better bet. I assume that this is why the studies above tend to stick with pain relief for evaluating placebos. Pain relief is easy to judge and quantify on a personal level, and the lack thereof does not threaten anyone's life. If you are injured and in pain, there is your test.
If you are not injured, however, and have no desire to be,14 you may want to try medication that causes noticeable benefit rather than treatment. For example, caffeine. Find two coffees, one caffeinated, one decaffeinated, that you can't tell tell apart with taste alone. Ideally, add something with a strong taste masking ability to each to help prevent differentiation. Have a friend divide up the two coffees into numbered plastic bags, one bag for each day of the experiment, without you knowing which bags are which. Also, it is important to prevent bias that you not be able to connect different days of the experiment, so no evens and odds. Your friend's numbering system should be sufficiently random that you can't figure out which bags are which. When you are ready, begin the experiment, using a bag of your choice for each day of the experiment. Chart, on an hourly basis, the amount of "buzz" you experience from that coffee number, and after maybe a month try to take a guess using the chart at which bag numbers were caffeinated and which were decaffeinated. Then, ask for your friend's table of which were which, and evaluate.
This was just a suggestion, but this and similar study designs should by all means allow you to test the placebo effect on yourself. Feel free to experiment, that's how science progresses.