Placebo and High Blood Pressure

Placebo effect in the treatment of high blood pressure

Placebo is talked about a lot, but what exactly is it? And can it happen with high blood pressure too?

First, the facts. The word "placebo" comes from Latin and literally means "I will please." By definition, a placebo is a medication that looks and tastes like a real drug but does not contain its active ingredients. A treatment can also be a placebo if its mechanism cannot be scientifically explained but its effect can be demonstrated, as can a sham operation that is not actually performed.

What is the placebo effect?

The placebo effect is thus defined as the measurable effect triggered by the patient's expectations of the medicine or treatment, even though it does not actually contain an active ingredient or have an effect that can be explained.

This kind of effect from placebos and sham treatments has already been demonstrated in many scientific studies.
A placebo effect could even be clearly shown when patients knew that the medication contained no real active ingredient and was therefore only a placebo. This was clearly demonstrated in open-label studies, for example in pain therapy at Harvard Medical School.

Open, empathetic communication by the healthcare professional turned out to be especially important for a positive placebo effect. Individual past experiences, social learning and media influence also affect how well placebo therapy works.

There is no body system for which a placebo effect cannot be described. In clinical trials, placebos are used to compare the effectiveness of, for example, a new drug with the pure placebo effect. Interestingly, symptoms also always improve in the study's so-called "placebo arm," that is, in patients who did NOT receive the original drug. Most of these are double-blind studies, meaning neither the patient nor the clinician knows who receives the active drug and who receives the placebo.

So the placebo effect has already been scientifically demonstrated and documented in many areas, for example in pain treatment, in hormonal and immunological responses, and in mental disorders.

But the cardiovascular system is also responsive to placebo mechanisms. Several studies have also shown placebo effects on blood pressure, both from interventions (e.g. verbal instructions) and from placebo medication and even sham procedures.

In several controlled drug trials, some patients with high blood pressure in the placebo control group reached target blood pressure without ever receiving the "real" drug. Some of those studies were small and often also highly selective (for example, only male participants). The picture is also not always clear for longer-term effects.
For example, a meta-analysis (that is, a summary of several studies) of all available studies of beta blockers (blood-pressure-lowering drugs) with parallel placebo control groups was performed (23 studies, 11,067 patients with high blood pressure). Control groups are used to determine the actual effect of the drug minus the part due to the placebo effect. Significant blood pressure reductions were seen in the placebo group as well, already accounting for 34% of the systolic and 47% of the diastolic reduction caused by the medication. Interestingly, higher-quality studies with more frequent interaction between patients and healthcare professionals were also associated with a stronger placebo-related blood-pressure-lowering effect.

Another analysis from the Royal Brompton Hospital in London showed that a sham therapy lowered blood pressure by an average of 6 mmHg. In patients with therapy-resistant high blood pressure, placebo pills or fake procedures even produced 913 mmHg lower readings.
Some experience even suggests that placebo treatments lower blood pressure more the more dramatic or invasive they appear to the patient.

And what is nocebo?

Nocebo, also from Latin, literally means "I will harm." It is the counterpart to the placebo and describes the fear of side effects from a medicine or other treatment. An inactive placebo can also trigger these unwanted effects and act like a reversed placebo effect.
A good example is a study with the beta blocker metoprolol for lowering blood pressure in male patients. Among those who were informed about the possible side effect of erectile dysfunction, 32 percent reported this side effect, while only 13 percent of the group who were told only the drug's name reported sexual impairment, compared with just 8 percent of patients in the group who were not told the drug's name at all.

Patients who are poorly informed about the benefits and possible side effects of a therapy and who may not have a trusting relationship with their healthcare provider often take their medication irregularly or not at all because they fear side effects, especially given the initially preventive nature of high blood pressure treatment, or stop taking it again on their own due to side effects also caused by the nocebo effect. Treating what is considered therapy-resistant high blood pressure then ultimately fails because of the patient's so-called non-adherence.

So choose a family doctor you trust and with whom you can discuss your worries and fears. The internet alone is not enough to reliably learn about the effects and side effects of a prescribed therapy.

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This article is from Tensana – the leading app since 2011, helping hundreds of thousands of people monitor their blood pressure every day. Our content is based on carefully researched, evidence-based data and is continuously updated (as of 12/2025).

Author Dr. med. Christine Berchtold-Benchieb is a specialist in general medicine who studied at LMU Munich and worked in a hospital as well as several general and specialist medical practices. Her many years of daily care for patients with high blood pressure combines evidence-based expertise with practical experience and ensures reliable recommendations.

We hope you found the article helpful. For good blood pressure control, it's important to take your medications correctly. Our app Tensana will gladly remind you when to take them. It also keeps track of your medication supply and notifies you in time when you're running low. This feature is fully available in the free version as well. Get the free app now.

Placebo and High Blood Pressure

What is the placebo effect?

And what is nocebo?

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