Soursop tea is an herbal tea brewed from the leaves of the soursop tree (Annona muricata), a tropical fruit tree native to Central and South America and the Caribbean. The tea has a mild, slightly earthy flavor and has been used in traditional medicine across tropical regions for centuries. It’s gained popularity worldwide due to claims about antioxidant, anti-inflammatory, and even anti-cancer properties, though many of these claims remain unproven in humans.
What Soursop Tea Is Made From
Soursop tea comes from the leaves of the soursop tree, not the fruit itself. The tree belongs to the Annonaceae family and grows in warm, humid climates throughout the tropics. You may also hear the fruit called graviola, guanábana, or Brazilian pawpaw depending on the region.
The leaves contain a class of compounds called acetogenins, which are long-chain fatty acids unique to this plant family. These compounds are the main reason soursop tea attracts scientific interest, and they’re also the source of its most serious safety concern. The leaves also contain flavonoids and other plant compounds with antioxidant activity.
How to Brew It
Soursop leaf tea can be made two ways, depending on how strong you want it.
The simpler method is steeping: use 3 to 5 fresh or dried leaves per cup, bring 8 to 10 ounces of filtered water to a boil, remove from heat, add the leaves, cover, and let steep for 8 to 10 minutes. For a milder cup, steep for 6 to 7 minutes or use fewer leaves.
The decoction method produces a stronger brew. Use 5 to 7 rinsed leaves per cup, place them in a saucepan with about 10 ounces of water, and bring to a gentle simmer. Let it simmer partially covered for 12 to 15 minutes, then strain. This method extracts more of the plant’s compounds, which also means a more bitter taste. Many people add honey or a squeeze of lime to balance the flavor.
Antioxidant and Anti-Inflammatory Properties
The most well-supported properties of soursop come from laboratory and animal studies showing genuine biological activity. Soursop leaf extract boosts the body’s production of an antioxidant enzyme called SOD1, which breaks down harmful molecules that cause cell damage. In diabetic mice, the leaf extract reduced markers of oxidative stress and indirectly supported insulin production.
The anti-inflammatory effects work through two pathways. Soursop compounds block the production of inflammatory signaling molecules (IL-1β, TNF-α, and IL-6) and inhibit COX enzymes, the same targets that aspirin and ibuprofen act on. In one study, soursop extract inhibited COX-2 activity by nearly 56% at moderate concentrations. It also reduced nitric oxide generation in a dose-dependent pattern, similar to vitamin C. In rats, these combined effects translated to measurable reductions in swelling.
The important caveat: these results come from concentrated extracts tested in lab dishes and rodents, not from people drinking cups of tea. The concentration of active compounds in a brewed cup is far lower than what’s used in these experiments, so it’s unclear how much of this activity carries over to everyday tea drinking.
The Cancer Claims
Soursop tea is frequently marketed as a natural cancer fighter, and this is where the gap between lab science and real-world evidence is widest. In laboratory settings, acetogenins from soursop have shown cytotoxic effects against more than 15 cancer cell lines, including drug-resistant ones. The compounds work by disrupting energy production in cancer cell mitochondria, depleting their fuel supply, and triggering programmed cell death.
None of this has been confirmed in human studies. No clinical trials of soursop as a cancer treatment have been completed. MD Anderson Cancer Center states plainly: “There is no strong evidence suggesting soursop can treat cancer in humans,” and the center does not recommend that cancer patients use soursop as treatment. Researchers are preparing early clinical trials for specific leukemia applications, but results are years away.
Killing cancer cells in a petri dish is a very low bar. Many common substances can do that, including bleach. What matters is whether a compound can selectively target cancer in a living human body without causing unacceptable harm, and soursop hasn’t cleared that hurdle.
Blood Sugar Effects
Animal studies consistently show that soursop reduces blood glucose levels. A systematic review found that across multiple rodent studies, soursop administered orally for 28 to 48 days significantly lowered blood sugar compared to controls, with effects described as similar to insulin. However, no human clinical studies met the review’s inclusion criteria, meaning there’s zero controlled evidence this works in people. If you take medication for diabetes, soursop tea could theoretically amplify glucose-lowering effects, though no formal drug interactions have been documented.
Neurotoxicity Risk
This is the most important safety consideration. Annonacin, the most abundant acetogenin in soursop, is a potent inhibitor of a key energy-producing structure inside brain cells. At very low concentrations in the lab, it depletes cellular energy and kills both dopamine-producing and other midbrain neurons. In rats, annonacin crosses into the brain and causes neurodegeneration in areas that control movement.
The human evidence is concerning. A study published in Movement Disorders found that consumption of any quantity of herbal tea made from Annonaceae plants worsened disease severity and cognitive deficits in people with degenerative parkinsonism, including Parkinson’s disease. The odds ratio was 2.91, meaning tea drinkers had roughly three times the odds of worse outcomes. Even low cumulative consumption of soursop fruit or juice (as little as one fruit every five days for a year) was associated with cognitive decline in this population.
This doesn’t mean a single cup of soursop tea will cause neurological damage. The risk appears tied to regular, long-term consumption. But the mechanism is well established at the cellular level, and the human observational data aligns with what the lab studies predict. Ironwood Cancer & Research Centers recommends using soursop tea occasionally rather than daily, specifically due to the potential for nerve toxicity with sustained use.
Who Should Be Cautious
People with Parkinson’s disease or a family history of parkinsonism should avoid soursop tea entirely, given the evidence linking it to worsened symptoms. Those taking blood sugar-lowering medications should be aware of soursop’s glucose-reducing effects in animal models, even though formal drug interactions haven’t been documented in humans.
Pregnant and breastfeeding women are generally advised to avoid soursop tea, as its safety hasn’t been studied in these populations. For everyone else, occasional consumption is likely low-risk, but daily, long-term use carries genuine uncertainty about cumulative neurotoxic effects that current science can’t fully quantify.