Yes, honest placebos can work. Here's how.
The evidence behind one of the most fascinating findings in modern medicine.
Where it started
2010
A 2010 Harvard study changed what we knew about placebos.
In 2010, a Harvard team invited eighty people with irritable bowel syndrome to join a surprisingly simple experiment. They were given pill bottles clearly labeled “placebo” but given an explanation on why they might still be helpful, then asked to take them twice a day for three weeks. After three weeks, the patients taking these placebo pills substantially outperformed those who took nothing at all. The placebo group showed larger mean improvements (e.g., IBS-GIS 5.0 vs 3.9; IBS-SSS reduction 92 vs 46 points). They knew the pills were inert, but they helped anyway—kicking off an entirely new field of research into honest placebos.
The mechanism
Three mechanisms grounded in neuroscience explain why honest placebos work.
Conditioned Expectation
Your body has spent a lifetime learning that engaging with pills, rituals, and care often precedes relief — and reading about people like you who have gotten better strengthens that learned response. This creates a new prediction in your brain: this might help me, because it's helped others.
Symptom Loop Reset
Functional symptoms create noisy feedback loops that amplify themselves — your body senses something off, your brain interprets it as danger, the alarm escalates. An honest placebo protocol can interrupt these loops, giving your nervous system a chance to recalibrate.
The Reward of Action
Choosing to take action activates reward pathways in the brain. Neuroscience shows that the act of doing something feels measurably better than doing nothing — like when you decide to take a different route due to traffic. You feel better when you have ownership over your life.
Honest = Deceptive
2021
Honest placebos can match deceptive ones.
The two placebo groups improved by the same amount — confirming the seminal 2010 result.
The double-blind trial — where neither patient nor doctor knows which pill is which — is the standard for proving a drug works. In 2021, Harvard Medical School ran a trial with 262 IBS patients over six weeks with three groups: open-label placebo, double-blind placebo, or no treatment at all. The two placebo groups improved by the same amount (69% vs. 70%) confirming the results originally obtained in the seminal 2010 study.
Lembo A. et al. (2021). “Open-label placebo vs double-blind placebo for irritable bowel syndrome.” PAIN. View study →
Framing matters
How a placebo is framed changes how it works.
Researchers in Basel and Harvard recruited 160 healthy volunteers, exposed their forearms to increasing heat, and gave everyone a dummy “pain relief” cream. One group was told the cream contained medicine, another was told it was a placebo but given a detailed explanation of how placebos can still help, a third got an open-label placebo with no explanation, and a fourth got no cream at all. Objectively, pain tolerance didn't change much. But people who received either the deceptive cream or the well-explained open-label placebo reported less intense, less unpleasant pain than those given an unexplained placebo. The story and rationale around a placebo can matter just as much as whether you're “in on” the fact that it's a placebo.
Locher C. et al. (2017). “Is the rationale more important than deception? A randomized controlled trial of open-label placebo analgesia.” PAIN. View study →
The evidence, by condition
Research-backed results across five specific conditions.
The other half
Handwriting changes how you think.
A Copables protocol is designed around physical interaction — in addition to your placebo, you'll complete a daily card by hand, grounded in cognitive behavioural therapy, the most evidence-backed treatment in mental health.
The physical act of writing forces you to process your thoughts more deeply, allowing new patterns to take hold.
Who responds best
Who responds best to OLPs.
The OLP responder literature is young, but three predictors have replicated across multiple trials.
People who understand the science.
You don't have to believe the protocol will work for you specifically. You just have to find the science behind it credible enough to engage with. People who score the rationale as plausible respond more strongly than those who don't.
People who want to take back control.
OLP works best for people in an active stance toward their condition rather than a passive one. Across multiple trials, people who feel they're taking action on their symptoms benefit more than people in a watchful-waiting frame.
People who actually show up.
The strongest predictor of OLP response is behavioural adherence — people who do the protocol get the protocol's effects. Belief in whether it will work doesn't predict outcome. Willingness to show up, day after day, does.
The studies
Peer-reviewed research.
Every Copables protocol is designed from the research of the world's leading scientific institutions — the studies that shaped our understanding of Open Label Placebos (OLPs).
Each study below answers a question the one before it raises.
Placebos can work even when you know.
Eighty IBS patients were told plainly that their pills were inert sugar pills, and asked to take them anyway — twice a day, for three weeks. After three weeks, they were doing roughly twice as well as the patients who took nothing.
Read paper →Brain scans show OLPs create legitimately different brain activity.
In an fMRI study, an honest-placebo group reported less distress to upsetting images — and three brain regions lit up differently, the same regions that quiet down under real anti-anxiety medication. A parallel result showed a 22% reduction in negative emotions versus control.
Read paper →How the placebo is framed changes how the placebo works.
Across multiple migraine attacks, the same chemical produced different amounts of relief depending on what the envelope said. A sugar pill honestly labelled “placebo” still produced more than half the pain relief of the real drug. The label is part of the medicine.
Read paper →An honest placebo can match a deceptive one.
262 IBS patients, six weeks, three groups. The open-label placebo group and the double-blind placebo group improved by the same amount — statistically, you couldn't tell them apart. Hiding the pill didn't make it work better.
Read paper →Open-label placebo for premenstrual symptoms.
A 2025 randomized controlled trial reported a 79% reduction in PMS symptoms.
Read paper →Open-label placebo and performance anxiety.
A 46% reduction in anxiety-induced test failure. Driving-test failure dropped from 53% to 29%.
Read paper →Open-label placebo for cancer-related fatigue.
29% improvement in fatigue severity in cancer survivors, and a 39% improvement in fatigue-disrupted quality of life.
Read paper →Cognitive behavioural therapy and lasting remission.
Across guided CBT trials for depression and anxiety, 52% achieved lasting remission at 12-month follow-up — versus 39% for treatment-as-usual.
Read paper →Why try it
A sensible place to start.
Open-label placebos don't work for everyone — but they're a low-stakes intervention that might. If you're serious about wanting to feel better, we'd recommend trying this lightweight approach before moving on to more drastic measures.