The Business of Selling Hope
Ineffective Supplements, Creams, and the Placebo Effect".
September 29, 2026 · Martina Berger
When Does a Treatment Really Work?
We are living in an extraordinary time for weight-loss medicine. Drugs such as semaglutide and tirzepatide have demonstrated substantial weight loss in clinical trials, while newer drugs such as retatrutide are being studied using the same scientific methods.
But walk through a store or spend ten minutes online, and you enter a different world.
There are creams promising to shrink belly fat, supplements claiming to boost metabolism, weight-loss patches, detox products, teas, and powders. Some contain ingredients with biological effects, some have weak evidence behind them, and others may do very little.
And yet people say:
“It worked for me.”
As a scientist, I find that fascinating, because what does worked actually mean?
Imagine buying a weight-loss pill that has no proven effect, but you truly believe it will help you. Every morning when you take it, you are reminded that you are trying to lose weight. Maybe you start eating a little better, skip the dessert you would normally have, drink more water, or go for a walk. A month later, you have lost five pounds.
You may give the pill the credit.
But perhaps the pill didn't change your metabolism. Perhaps believing in the pill helped change your behavior.
That doesn't make the weight loss imaginary. You really did lose weight. The question is what actually caused it.
And that is where the placebo effect becomes much more interesting than simply dismissing something as “all in your head.”
The Power of Expectation
In the 2011 Mind Over Milkshakes study, participants drank the same 380-calorie milkshake on two different occasions. One time, they were told it was an indulgent 620-calorie shake; another time, they were told it was a light 140-calorie shake.
But the shake was exactly the same.
Researchers measured ghrelin, a hormone involved in hunger. When participants believed they had consumed the rich, high-calorie shake, their ghrelin levels dropped much more sharply than when they believed they had consumed the light shake.
The calories and nutrients had not changed, but their hormonal response did. What changed was their expectation.
This does not mean we can think ourselves thin or replace medical treatment with belief. But it does suggest that expectation can influence both our behavior and, at least in some circumstances, measurable responses in our bodies.
So Is It Wrong to Sell Hope?
Now the question becomes more complicated.
Suppose that weight-loss pill contains nothing that actually causes weight loss, but taking it motivates someone to eat better, exercise more, and believe that change is possible.
She loses weight.
Did the pill “work”?
In one sense, no—the product did not produce the biological effect it promised.
But in another sense, buying it may have helped trigger the behaviors that produced a real result.
That is the strongest argument for what we might call harmless hope. Hope can motivate us, and sometimes believing that we have finally found something that will help us may be enough to get us started.
But there is still an ethical problem.
The person buying the supplement isn't being told, “This pill may motivate you to take better care of yourself.”
She is being told, “This product will change your body.”
If that claim isn't supported by evidence, someone is making money from her belief without telling her what she is actually buying.
And when the product stops “working,” she may not blame the product.
She may blame herself.
There can also be real risks. The FDA has identified weight-loss products containing hidden ingredients that were not disclosed on their labels. An ineffective product is therefore not necessarily a harmless one.
The problem isn't that belief helped.
The problem is profiting by misrepresenting why it helped.
The Honest Placebo
Here is the part I find most fascinating: What if placebo effects do not always require deception?
In a small 2010 study, people with irritable bowel syndrome were given pills openly labeled “placebo pills” and were told that they contained an inert substance. Yet the group taking the open-label placebos reported greater improvement in several symptoms than the group receiving no treatment.
This does not prove that open-label placebos cause weight loss, but it raises an intriguing possibility:
Maybe we do not have to choose between hope and honesty.
There is a big difference between saying:
“This pill will do it for you.”
and
“This ritual may help you show up for yourself.”
To me, that is the difference between encouraging belief and exploiting it.
Believing Wisely
I don't want to become more cynical because belief can be exploited. I don't want to stop hoping, and I certainly don't want to stop believing.
I want to become better at deciding what deserves my belief.
When a product promises an easy solution, I want to ask whether there is independent evidence behind it, whether I am buying something that actually works or simply buying motivation, and who profits from convincing me to believe.
Because belief really can be powerful.
That is precisely why it deserves to be treated with respect.
The lesson isn't to believe less. It is to believe wisely—and to put our faith in things that are true.
Sources
National Institutes of Health, Office of Dietary Supplements. Dietary Supplements for Weight Loss.