Chaga has not been proven to lower blood pressure in humans. No clinical trials have tested its effect on blood pressure, and the evidence that exists comes entirely from lab and animal studies. While chaga contains compounds that could theoretically influence blood vessel function, there is currently no reliable basis for using it as a blood pressure treatment.
What the Research Actually Shows
A review of human clinical trials on chaga found only two published studies, and neither one measured blood pressure. One treated psoriasis, the other treated peptic ulcers. This is a significant gap. Without controlled human trials, any claims about chaga lowering blood pressure remain speculative.
For comparison, reishi mushroom (a related medicinal mushroom) has been tested in several human trials with doses ranging from 330 mg to 5,400 mg per day, and some of those studies did show modest blood pressure reductions. Chaga simply hasn’t been put through the same testing. A study on another medicinal mushroom species found no detectable changes in blood pressure compared to placebo, which is a reminder that “promising lab results” don’t always translate to real effects in people.
Why Some People Think It Might Help
Chaga contains several compounds that affect the cardiovascular system in laboratory settings, which is where the interest comes from. The most studied is betulinic acid, a compound found in chaga’s outer crust (absorbed from the birch trees it grows on). In a rat study, betulinic acid reduced blood pressure in animals with induced hypertension, bringing elevated readings down from about 135 mmHg. It worked by helping blood vessels relax, specifically by reducing oxidative stress and preserving nitric oxide, a molecule your body uses to widen blood vessels.
Certain mushroom species also produce peptides that block an enzyme called ACE, which plays a central role in regulating blood pressure. ACE inhibitors are one of the most common classes of blood pressure medication. While this mechanism has been demonstrated in other edible mushrooms, it hasn’t been specifically confirmed in chaga.
Chaga also has a notable potassium content, with potassium making up roughly 50% of its total mineral content and about 9 to 10% of its dry weight. Potassium helps counterbalance sodium and supports healthy blood pressure. However, the amount you’d get from a typical cup of chaga tea is small compared to dietary sources like bananas or potatoes, so this is unlikely to have a meaningful impact on its own.
Safety Concerns Worth Knowing
Even if you’re taking chaga for general wellness rather than blood pressure specifically, there are real risks to be aware of.
The most serious documented concern involves kidney damage. Chaga contains extremely high concentrations of oxalates, compounds that can crystallize in the kidneys. In one published case, a person who consumed 4 to 5 teaspoons of chaga powder daily for six months developed severe kidney failure requiring dialysis. A biopsy showed widespread damage from oxalate crystal deposits. This is an extreme case involving high daily intake over months, but it illustrates that chaga is not harmless in large amounts.
Chaga also inhibits platelet aggregation in animal models, meaning it may thin the blood. If you take blood thinners or antiplatelet medications, chaga could amplify their effects. The clinical significance of this interaction hasn’t been established in humans, but the theoretical risk is enough that oncology sources flag it as a concern. The same applies to blood sugar: chaga has shown blood sugar-lowering properties in lab studies, so combining it with diabetes medications could theoretically cause levels to drop too low.
What This Means Practically
If you’re dealing with high blood pressure and wondering whether chaga could help, the honest answer is that nobody knows yet. The biological plausibility is there: betulinic acid relaxes blood vessels in rats, some mushrooms inhibit a key blood pressure enzyme, and chaga is rich in potassium. But plausibility is not evidence. Many compounds that look promising in the lab fail to produce meaningful effects in people, and chaga hasn’t even reached the stage of being tested.
Drinking a cup of chaga tea occasionally is unlikely to cause harm for most people. But relying on it to manage blood pressure, or consuming large amounts in powder form, introduces real risks (particularly to your kidneys) without proven benefits. The gap between what chaga might do and what it’s been shown to do in humans remains wide.