Several widely available herbs can raise blood pressure, some significantly. The most well-documented are licorice root, ephedra (ma-huang), ginseng, guarana, bitter orange, and yohimbe. Whether you’re trying to avoid a blood pressure spike or wondering what’s behind an unexplained rise in your readings, these are the herbs that matter most.
Licorice Root
Licorice root is the herb most consistently linked to elevated blood pressure, and the effect can be dramatic. The active compound in licorice blocks an enzyme in your kidneys that normally keeps cortisol from acting like aldosterone, the hormone that tells your body to hold onto sodium and water. When that enzyme is blocked, cortisol floods the same receptors aldosterone normally uses, and your body starts retaining sodium, shedding potassium, and driving up blood pressure. This mimics a condition called hyperaldosteronism, even though aldosterone levels themselves are normal.
The tricky part is that there’s no universal “safe” amount. How strongly licorice affects your blood pressure depends on your age, sex, whether you already have high blood pressure, and how your gut processes the active compounds. People who already run high are more vulnerable. Licorice shows up not just in supplements but in certain teas, candies, and chewing tobaccos, so the exposure can be easy to miss.
Ephedra (Ma-Huang)
Ephedra is one of the most dangerous herbs for blood pressure. It acts as a powerful stimulant, constricting blood vessels and increasing heart rate. The FDA received over 800 reports of serious adverse events linked to ephedra, including heart attacks, strokes, seizures, and deaths. Many of these involved dangerously high blood pressure. Several U.S. states banned its sale, and the FDA pulled ephedra-containing dietary supplements from the market in 2004.
Despite the ban, ephedra still turns up in products sold online or imported from other countries, sometimes under its Chinese name ma-huang. It was once a staple of weight-loss and energy supplements, and some formulations still circulate outside mainstream retail.
Bitter Orange
After the ephedra ban, bitter orange (also called Citrus aurantium or Seville orange) became one of the most common replacements in “ephedra-free” weight-loss supplements. It contains synephrine, a compound with stimulant-like effects on the cardiovascular system. In a controlled study, a single dose of bitter orange extract raised systolic blood pressure by about 7 mmHg compared to placebo, with the effect lasting up to five hours. Heart rate also increased by roughly 4 beats per minute. The blood pressure bump may sound modest, but for someone already managing hypertension, that sustained five-hour elevation adds meaningful strain.
Guarana
Guarana contains roughly twice the caffeine concentration of coffee beans, and it raises blood pressure in a way that lasts longer than you might expect. In a head-to-head comparison with coffee and yerba mate, guarana was the only one that significantly increased systolic blood pressure, and its effects were still measurable more than two and a half hours after consumption. Diastolic pressure didn’t change significantly, so the impact is mainly on the top number in your reading.
Guarana is a common ingredient in energy drinks, pre-workout supplements, and weight-loss products, often combined with other stimulants. That stacking effect can amplify the blood pressure response beyond what guarana alone would cause.
Yohimbe
Yohimbe, derived from the bark of an African tree, is marketed for weight loss and sexual performance. Its active compound blocks a type of receptor in the nervous system that normally helps regulate blood pressure. In a study of healthy men, a single 20-mg dose of yohimbine raised systolic blood pressure by about 13 mmHg and diastolic by about 8 mmHg within 90 minutes. That’s a substantial jump from one dose in people who started with normal readings. It also impairs the body’s normal reflex for slowing heart rate when blood pressure rises, which means the cardiovascular system gets hit from two directions at once.
Ginseng
Both American ginseng and Asian (Panax) ginseng appear on the Mayo Clinic’s list of herbs that can affect blood pressure. The evidence is more mixed than for licorice or ephedra. Some studies show modest blood pressure increases, while others suggest ginseng may actually lower it depending on the type, dose, and duration of use. The concern is real enough that people on blood pressure medication are generally advised to disclose ginseng use to their healthcare provider, since it may interfere with how those medications work.
Arnica
Arnica is primarily used topically for bruises and muscle soreness, but oral forms exist in some herbal preparations and homeopathic products. Taken internally, arnica can raise blood pressure. Topical use at normal concentrations is unlikely to have a systemic effect, but concentrated oral supplements or tinctures carry more risk.
Herb-Drug Interactions That Spike Blood Pressure
Some herbs don’t raise blood pressure on their own but become dangerous when combined with certain medications. St. John’s wort is the clearest example. When taken alongside a class of antidepressants called MAOIs, St. John’s wort can trigger serotonin syndrome, a condition that includes rapid heart rate, major swings in blood pressure, high fever, and confusion. The interaction can also occur with certain pain medications.
MAOIs also interact badly with tyramine, an amino acid found in aged and fermented foods. Herbal teas and supplements made from fermented plant materials can contain enough tyramine to cause a sudden, dangerous blood pressure spike in someone taking an MAOI. This type of hypertensive crisis can come on fast and without much warning.
How to Spot the Problem
Herb-induced blood pressure elevation often looks identical to regular high blood pressure on a standard reading. You won’t feel it most of the time. The key difference is the timeline: if your blood pressure rose after you started a new supplement, tea, or herbal product, the herb is the most likely explanation. Licorice in particular can cause low potassium alongside high blood pressure, which may show up as muscle weakness, cramps, or fatigue. If stopping the herb brings your numbers back down within days to weeks, that essentially confirms the connection.
Many of these herbs appear as ingredients in blended products like energy drinks, weight-loss capsules, or “natural” performance boosters, where they may not be prominently labeled. Checking the full ingredient list matters, especially if your blood pressure has changed without an obvious reason.