The placebo effect is not just a patient's illusion

A friend told me his back pain had disappeared thanks to a magnetic bracelet. I replied that it was the placebo effect, with the slightly satisfied tone that usually comes with false statements. He asked me what exactly that meant. I realised I didn’t know, and that I’d used the word to end the conversation.

What the word actually refers to

A placebo, strictly speaking, is an intervention with no specific active ingredient for the condition in question. The placebo effect is the change observed in the person after that intervention. The two are often confused, and that confusion produces a lot of nonsense.

Part of the change is nothing mysterious. Many symptoms fluctuate on their own: a pain rises and falls, a cold runs its course. If you measure someone at the peak of their discomfort, the next measurement will be lower whatever you do. There’s also what people report: they readily tell an attentive carer that they feel better. Both effects end up in the numbers and inflate what gets credited to the placebo.

What remains after that clean-up is more interesting. For pain, nausea and certain sleep disorders, a measurable response persists, with biological correlates identified in the brain’s opioid and dopamine circuits. The expectation of relief changes how a signal is processed. It’s not a belief replacing biology, it’s a belief that works through biology.

The limits, often glossed over

Placebo acts on perception and on systems regulated by the brain. It doesn’t shrink a tumour, lower a viral load, or mend a fracture. An asthmatic on placebo reports breathing better, and their lung function measurements don’t move. That dissociation is the most useful thing to remember, because it separates the comfort you feel from the problem being treated.

Another nuance rarely mentioned: the effect is stronger when the ritual is more impressive. An injection works better than a tablet, a device better than words, a confident practitioner better than a hurried one. The setting is part of the medicine.

Who benefits from the ambiguity

This is where the matter becomes economic. An entire market rests on products whose specific effectiveness has never been shown, and which sell very well: supplements, devices, unregulated consultations, wellness subscriptions. These products aren’t reimbursed, so the person pays for them in full, and they largely escape the evaluation requirements that apply to a drug.

The commercial logic is elegant. If the product relieves, testimonials are highlighted. If it doesn’t, the fault lies with a lack of regularity or conviction. The placebo mechanism guarantees a steady stream of satisfied people, enough to keep a business model running without ever having to prove anything.

At the same time, the honest part of the placebo effect, the part that comes from time spent with a patient, from explanation, from trust, is precisely what healthcare systems cut first for reasons of productivity. The ritual is billed dearly in the private sector, and the consultation is squeezed in the public one.

What I eventually told him

I called my friend back. I told him his back might really be better, that the bracelet probably had nothing to do with it, and that both statements can be true at once. He kept the bracelet, which seems reasonable for twenty euros.

What bothers me isn’t that he believes it. It’s that someone has built a revenue model on a brain mechanism that would have worked perfectly well for free.