Iranian researchers found that saffron extract, crocin and safranal lowered mean arterial blood pressure in anaesthetised rats. The experiment was useful pharmacology, but it did not show that saffron tea treats hypertension in people and its intravenous doses are not instructions for human use.
This article traces that Mashhad University study accurately, corrects several mistranscribed doses and results in the old version, and places the animal findings beside newer human evidence.
The Iranian saffron and blood pressure study
The paper was written by Mohsen Imenshahidi, Hossein Hosseinzadeh and Yaser Javadpour of the School of Pharmacy at Mashhad University of Medical Sciences. The former article rendered Imenshahidi’s name as “Mohsen Ayman Shahidi”; the publication record gives the correct spelling.
The study, published in Phytotherapy Research, compared normal rats with rats whose hypertension had been induced using desoxycorticosterone acetate, usually abbreviated DOCA. The animals were anaesthetised while researchers measured mean arterial blood pressure and heart rate.
What the researchers administered
Three test materials were given intravenously in separate groups:
- crocin at 50, 100 or 200 mg per kilogram of body weight;
- safranal at 0.25, 0.5 or 1 mg/kg;
- an aqueous saffron-stigma extract at 2.5, 5 or 10 mg/kg.
The old article duplicated 0.5 mg/kg in the safranal list and blurred the other dose ranges. These corrected figures come directly from the paper’s abstract.
“Intravenously” is an essential detail. A substance placed directly into a vein has different absorption and peak exposure from saffron eaten in food or steeped in water. Milligrams per kilogram in rats cannot be converted into a home dose by simple arithmetic.
What the rat experiment found
The aqueous extract, crocin and safranal reduced mean arterial blood pressure in both normal and DOCA-hypertensive rats in a dose-dependent manner. At the highest tested amounts, the reported average reductions were:
- 60 ± 8.7 mmHg after 10 mg/kg aqueous extract;
- 50 ± 5.2 mmHg after 1 mg/kg safranal;
- 51 ± 3.8 mmHg after 200 mg/kg crocin.
The previous translation turned these values into an unreadable string. Restoring the numbers does not make them human outcomes: they describe an acute response in anaesthetised animals after intravenous administration.
The researchers concluded that aqueous saffron-stigma extract had hypotensive activity in this model and that crocin and safranal contributed. They considered safranal the more important of the two for lowering rat blood pressure under the tested conditions.
Crocin and safranal are not interchangeable
Crocin is one of the carotenoid pigments responsible for saffron’s red-gold colour. Safranal is a volatile compound associated with its aroma. Calling both simply “active ingredients” can imply that a normal serving contains the concentrations or exposure used in an experiment. It does not.
An extract’s composition depends on raw material, solvent, processing and standardisation. A whole spice, an aqueous laboratory extract, isolated crocin and isolated safranal are four different interventions.
What human trials say about saffron and blood pressure
Later researchers pooled randomised trials in people. The average effects are far smaller than the dramatic numbers from the rat study.
A 2025 meta-analysis of 25 trials in people with metabolic syndrome or related disorders reported average changes of about −1.15 mmHg systolic and −1.61 mmHg diastolic compared with placebo. The authors asked for more high-quality trials in diverse populations.
Another 2025 GRADE-assessed review focused on diabetes and prediabetes. It found a systolic signal but no significant diastolic effect and explicitly judged the observed blood-pressure change not clinically important. These findings do not establish saffron as an antihypertensive medicine.
Why a small average change is not a treatment plan
Blood pressure varies with measurement technique, stress, activity, sleep, medicines and time of day. A pooled average of one or two mmHg across selected trials cannot tell an individual to replace a prescribed drug, and it says nothing about emergency treatment.
The US Centers for Disease Control and Prevention notes that high blood pressure often has no warning signs and raises the risk of heart disease and stroke. Diagnosis depends on correctly taken readings, not symptoms or whether a person feels calmer after a drink.
- Do not stop or reduce blood-pressure medicine because of a saffron study.
- Ask a clinician or pharmacist before a concentrated supplement, especially with several medicines or a tendency to low blood pressure.
- Use a validated cuff of the correct size and follow the measurement instructions.
- Record readings over time if a clinician asks; one unusual reading is not a trend.
- Seek urgent help for a very high reading accompanied by chest pain, severe breathlessness, weakness, confusion, vision change or another acute symptom.
Food use, tea and supplements
A modest amount of saffron in food can be enjoyed for flavour and colour. A tea or infusion still has an unknown dose unless the material is weighed and characterised, and even a measured culinary drink does not reproduce an intravenous rat experiment.
Supplements add another layer of uncertainty: composition and concentration may differ between brands. A 2026 review of saffron adverse events found medicinal preparations generally tolerated in trials, with gastrointestinal complaints among the most frequent problems. People taking antihypertensive medicine need to consider the possibility of additive effects rather than assuming “natural” means harmless.
What this Iranian research established
The Mashhad team showed that aqueous saffron extract, crocin and safranal could acutely lower mean arterial blood pressure in a specific rat model. It provided a basis for further research. It did not establish a human dose, a tea recipe, long-term safety or an alternative to hypertension care.
That is the accurate way to describe Iranian researchers on the effect of saffron on lowering blood pressure: an important preclinical observation followed by human evidence suggesting only small average changes.
