The short version:
-
In several randomized studies, people who knowingly took a placebo reported feeling less stressed or less upset than people who took nothing.
-
The effects were mostly on how people said they felt. Objective body measures, like heart rate or cortisol, usually didn’t budge.
-
The studies were small and short, so an honest placebo might help you feel calmer, and it might not.
Stress is one of the most searched-for problems on the internet, and for good reason. Most of us carry some level of stress all the time, so it’s fair to ask whether a pill you know is a placebo could take a little of the edge off.
It sounds like it shouldn’t work. A placebo has no active ingredient, and, for an honest placebo, you know it has no active ingredient when you take it. But a growing set of studies has tested exactly this question, and the results are more interesting than you might expect. Here’s what they found, with the numbers and the caveats.
What “honest placebo” means here
An honest placebo, also called an open-label or non-deceptive placebo, is a pill, spray, or cream with no active drug, given to someone who is told plainly that it’s a placebo. Nobody is tricked. In most studies, people also get a short explanation of how placebo effects work, and they’re told they don’t have to believe in it for it to have a chance of helping.
If you’re new to the idea, our earlier post, What Is an Open-Label Placebo? What the Research Really Shows, covers the background and the early trials.
Study 1: Placebos reduced distress, in self-reports and in brain signals
In 2020, researchers at Michigan State University and the University of Michigan published two experiments in Nature Communications (Guevarra et al., 2020).
Participants looked at a series of upsetting images. Before viewing, one group read about placebo effects and used a saline nasal spray that they were told was a placebo with no active ingredients, but that it might reduce their negative reactions if they believed it would. The control group used the same spray but were told it was there to improve the clarity of the physiological recordings.
What they found:
-
In the first experiment, the honest-placebo group reported less emotional distress while viewing the negative images.
-
In the second experiment, the honest-placebo group also showed a smaller sustained “late positive potential,” a brain signal measured by EEG that tracks how strongly people process emotional images.
That second result matters because it suggests the effect isn’t only people telling researchers what they think they want to hear. A later study by a different team reported a similar reduction in that brain signal.
The limits: this was a lab task lasting minutes, with healthy college-age volunteers looking at pictures. It tells us something real about how the brain responds, but it isn’t the same as everyday life stress.
Study 2: Two weeks of placebo pills during prolonged stress
A 2024 trial took the idea out of the lab (Guevarra et al., 2024, Applied Psychology: Health and Well-Being). The researchers recruited people who were experiencing prolonged stress during the COVID-19 pandemic and randomly split them into two groups.
-
The honest-placebo group watched short videos about placebo research, met with a researcher over Zoom, and got placebo pills in the mail to take twice a day for two weeks.
-
The control group met with a researcher and answered the same questionnaires, but took no pills.
What they found: after two weeks, the placebo group reported significantly larger drops in COVID-related stress, overall stress, anxiety, and depression scores than the control group. The researchers also reported that participants found the routine easy, acceptable, and a good fit for their situation.
The limits, honestly:
-
It was a small trial, and it only lasted two weeks.
-
The control group took nothing at all, so some of the difference may come from the extra attention, the videos, and the daily ritual, not the pill itself.
-
It’s a single study, so it needs to be repeated by other researchers before anyone can be confident in it.
-
Everyone knew which group they were in, and all the outcomes were self-reported.
What happens when you pool the studies?
Single studies can be flukes, so it helps to look at reviews that combine many of them. In 2023, a team in Germany pooled experiments that tested honest placebos in healthy people, not patients (Spille et al., 2023, Scientific Reports). They found 20 studies with 1,201 participants, covering well-being, stress, sadness, test anxiety, pain, itchiness, and more.
The headline numbers:
-
For self-reported outcomes (how people said they felt), honest placebos had a significant small-to-moderate effect: a standardized mean difference of 0.43, based on 13 studies.
-
For objective outcomes (physical or behavioral measurements), there was no effect: a standardized mean difference of essentially zero (−0.02), based on 8 studies.
To put 0.43 in plain terms: on average, people in the placebo groups felt somewhat better than the comparison groups, but there was a lot of overlap. Plenty of people in the placebo groups didn’t feel any different.
The authors were also candid that most studies had a moderate risk of bias and that the overall quality of evidence was low to very low. In other words, the signal looks real enough to take seriously, but it’s far from settled.
Why might an honest placebo ease stress?
Nobody knows for sure, but researchers point to a few likely ingredients:
-
Expectation. Even when you know a pill is inert, part of your mind can still anticipate relief. Expectations are known to shape how we feel.
-
Ritual and conditioning. Most of us have a lifetime of taking a pill and then feeling better. A small, deliberate routine can tap into that learned response.
-
A pause. Taking a capsule twice a day is a built-in moment to stop, breathe, and check in with yourself, which may be part of the benefit.
-
Meaning-making. The brain-signal findings in the 2020 study suggest honest placebos may change how strongly we appraise upsetting things, rather than how quickly we notice them.
The honest bottom line
Here’s what we think the evidence supports:
-
Across several small trials, people who knowingly took a placebo reported feeling less stressed or distressed than people who took nothing.
-
The average effect was modest, and many people didn’t notice a difference.
-
Objective stress measures (biological measures) mostly didn’t change.
-
The studies were short, small, and couldn’t blind participants, so better research is still needed.
An honest placebo is not a replacement for sleep, exercise, talking to someone, or professional care. If stress, anxiety, or low mood is affecting your daily life, please talk to a doctor or mental health professional, and don’t stop any treatment you’re on.
Trying it yourself
If you’re curious, an honest placebo is a low-cost, low-risk experiment. That’s why we make Magic Bullet Placebo Pills: 120 vegan capsules with no active ingredients, clearly labeled as placebos. If you want a longer run or want to share with someone, the Magic Bullet 2-Pack has 240 capsules.
A simple way to try it, modeled loosely on the routines in the studies:
-
Take a capsule at the same times each day, for example morning and evening.
-
Use the moment as a short pause: one slow breath, and a quick note of how you feel.
-
Keep it up for about two weeks, then honestly ask yourself whether anything changed.
For kids, bedtime worries are a common kind of stress. Magic Bullet JR chewable tablets and No Ghost repellent cream are made for gentle, honest bedtime rituals.
It might help, and it might not. Either way, you’ll know, and nobody had to fool you.
This article is for general information and isn’t medical advice. Progressive Placebo products contain no active ingredients and are not intended to diagnose, treat, cure, or prevent any disease.
Sources
-
Guevarra DA, Moser JS, Wager TD, Kross E. Placebos without deception reduce self-report and neural measures of emotional distress. Nature Communications. 2020. doi:10.1038/s41467-020-17654-y
-
Guevarra DA, et al. Remotely administered non-deceptive placebos reduce COVID-related stress, anxiety, and depression. Applied Psychology: Health and Well-Being. 2024. doi:10.1111/aphw.12583
-
Spille L, Fendel JC, Seuling PD, Göritz AS, Schmidt S. Open-label placebos: a systematic review and meta-analysis of experimental studies with non-clinical samples. Scientific Reports. 2023. doi:10.1038/s41598-023-30362-z
