Placebo and High Blood Pressure

Placeboeffekt bei der Behandlung von Bluthochdruck

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 act as a placebo if its mechanism cant be scientifically explained yet a measurable effect is observed this can even include a sham operation that isnt actually performed.

What is the placebo effect?

The placebo effect is the measurable change that occurs because of the patients expectations about a medicine or treatment, even though it contains no active ingredient or has no explainable mechanism.

This kind of effect from fake medications and sham treatments has been demonstrated in many scientific studies.
A placebo effect could even be clearly shown when patients knew the medicine contained no active ingredient for example, in open-label studies of pain therapy at Harvard Medical School.

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

Theres no body system in which a placebo effect hasnt been described. In clinical trials, placebos are used to compare the effectiveness of, for example, a new drug with the pure placebo effect. Interestingly, symptoms often improve in the trials "placebo arm" that is, in patients who did NOT receive the real drug. Most of these are double-blind studies, meaning neither the patient nor the clinician knows who gets the active drug and who gets 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.

The cardiovascular system is also responsive to placebo mechanisms. Several studies have shown placebo effects on blood pressure, both from simple interventions (e.g. verbal instructions) and from placebo medication or 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 or very selective (for example, only male participants). The picture is also not always clear for longer-term effects.
For example, a meta-analysis 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 groups as well amounting to about 34% of the systolic and 47% of the diastolic reduction caused by the medication. Interestingly, higher-quality studies with more frequent contact between patient and caregiver 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." Its 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 that side effect. In the group who were only told the drugs name, 13 percent reported sexual problems, and only 8 percent of patients who didnt hear the drug name reported such problems.

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 caregiver often take their medication irregularly or stop it because of fears of side effects. Due to side effects driven by the nocebo effect, some stop medication on their own. Treating what is labeled as therapy-resistant high blood pressure then ultimately fails because of the patients 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.

Sources:

This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands 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, studied at LMU Munich and has worked in hospitals as well as in several general and specialist practices. Her many years of daily care for patients with high blood pressure combine evidence-based expertise with practical experience and provide reliable recommendations.

We hope you found the article helpful. For good blood pressure control, it's important to take your medications correctly. Our app BloodPressureDB 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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