Soursop tea, made from the leaves of the tropical fruit tree, carries real risks for several groups of people. Pregnant women, anyone taking blood pressure or diabetes medications, and people with neurological conditions should avoid it or use extreme caution. While soursop has gained popularity for its potential health benefits, its active compounds are potent enough to cause serious interactions and side effects in vulnerable individuals.
Pregnant and Breastfeeding Women
Soursop leaf tea should be avoided during pregnancy. The University of Texas at El Paso’s herbal safety program lists this as a clear contraindication. The concern centers on compounds in the leaves that may stimulate uterine activity. There is also no reliable safety data for breastfeeding mothers, so the same caution applies if you’re nursing.
People Taking Blood Pressure Medication
Soursop leaf extract lowers blood pressure on its own, and combining it with prescription blood pressure drugs can push levels dangerously low. Animal studies have shown that the aqueous leaf extract significantly decreases both systolic and diastolic blood pressure in a dose-dependent way, meaning the more you consume, the greater the drop.
The mechanism appears to work similarly to calcium channel blockers, a common class of blood pressure medication. In one study, soursop extract at certain concentrations produced effects comparable to nifedipine, a widely prescribed calcium channel blocker. If you’re already taking any antihypertensive drug, adding soursop tea creates a stacking effect that could cause dizziness, fainting, or a dangerous drop in blood pressure. This applies whether you take calcium channel blockers, ACE inhibitors, beta-blockers, or diuretics.
If your blood pressure tends to run low even without medication, soursop tea could make that worse on its own.
People on Diabetes Medications
Soursop has demonstrated blood sugar-lowering effects in animal studies, which means it can amplify the effects of diabetes medications. Memorial Sloan Kettering Cancer Center specifically flags this interaction: taking soursop alongside drugs that lower blood sugar may not be safe because of the additive effect. If you’re managing diabetes with insulin or oral medications, drinking soursop tea on top of that could push your blood sugar low enough to cause hypoglycemia, with symptoms like shakiness, confusion, sweating, and in severe cases, loss of consciousness.
The clinical relevance in humans hasn’t been firmly established, but the risk is real enough that major cancer centers include it in their drug interaction warnings.
People With Parkinson’s or Neurological Conditions
This is one of the most serious long-term concerns with soursop. The leaves and fruit contain a compound called annonacin that can cross the blood-brain barrier and damage neurons in the basal ganglia, the brain region that controls movement. In rats given annonacin chronically, researchers observed neurodegeneration that closely resembled atypical parkinsonism, a condition seen at elevated rates in Caribbean populations where soursop consumption is high.
A research team publishing in the journal Movement Disorders confirmed that high concentrations of annonacin are present in both the fruit and water-based leaf extracts (which is exactly what soursop tea is). The compound was detected in the brain tissue of treated animals, confirming it doesn’t just stay in the gut or bloodstream. WebMD notes that multiple studies have linked soursop consumption to nerve damage with symptoms similar to Parkinson’s disease.
If you already have Parkinson’s disease, any movement disorder, or a family history of neurodegenerative conditions, soursop tea poses a meaningful risk of accelerating or worsening symptoms. Even for healthy individuals, heavy or prolonged use is a concern.
People With Mitochondrial Disorders or Chronic Fatigue
Soursop’s most studied active compounds, called acetogenins, work by blocking a specific step in how your cells produce energy. They inhibit Complex I in the mitochondria, which is essentially the first gear in your cells’ energy-production machinery. This causes a drop in ATP (your cells’ energy currency) and a buildup of damaging molecules called reactive oxygen species.
For cancer research, this mechanism is interesting because tumor cells need more energy than normal cells and are more vulnerable to this disruption. But for anyone whose mitochondria are already compromised, this is a problem. People with diagnosed mitochondrial disorders, chronic fatigue syndrome, or conditions that affect cellular energy production could experience worsened fatigue, muscle weakness, or other symptoms. At higher concentrations or with extended exposure, soursop compounds can cause irreversible mitochondrial damage.
People Undergoing Chemotherapy or Taking Other Medications
Because soursop affects so many systems simultaneously, including blood pressure, blood sugar, cellular energy production, and neurological function, it has the potential to interfere with a wide range of treatments. Its active compounds are biologically potent, not mild herbal supplements. If you’re on any prescription medication, the safest approach is to treat soursop tea as a drug interaction risk rather than a harmless beverage.
The liver processes many of soursop’s active compounds through the same pathways it uses for prescription drugs, which can alter how quickly or slowly your body metabolizes medications. This is especially relevant for people on chemotherapy, blood thinners, or any drug with a narrow therapeutic window where small changes in blood levels matter.
How Much Is Too Much
No established medical guideline sets a safe daily limit for soursop tea. The neurotoxicity research suggests that the risk increases with both the amount consumed and the duration of use. Occasional consumption by otherwise healthy adults appears to carry lower risk, but “moderation” remains vaguely defined because the concentration of active compounds varies between products, preparations, and even individual leaves.
The neurological effects in particular appear to require prolonged exposure, so someone drinking soursop tea daily for months or years faces a different risk profile than someone who has it occasionally. However, the blood pressure and blood sugar effects can happen acutely, with a single strong cup potentially causing problems for someone on medications.