Soursop (Graviola): a botanical guide

Soursop is the fruit of Annona muricata, a tropical tree of the custard-apple family. It is also listed in EFSA's compendium of botanicals reported to contain naturally occurring substances of possible concern for human health. That is why the safety section here is the longest part of the page, and why it is the part to read before you buy.

Latin binomial: Annona muricata L.
Plant family: Annonaceae
Part used: Leaf (capsules); full-spectrum soursop (drops)
Extract strength: 30:1, certified organic
Per serving: 450 mg (one capsule) or 600 mg (2 ml of drops)
Allergens: Free from common allergens; capsules are vegan

01 What soursop (graviola) is

The fruit is heart-shaped, green, covered in soft spines, and packed with white fibrous pulp. The tree carrying it is a small evergreen, native to the tropical Americas and the Caribbean, and now grown across the warm humid parts of South and Central America, the Caribbean, West Africa, and South and South-East Asia.

The name changes with the country. Soursop and graviola are the two you meet in English-language retail. In Spanish-speaking countries it is guanábana; in the French Caribbean, corossol.

Different parts of the tree go different ways. The fruit is eaten fresh, or pressed into juices and nectars. The leaf is what gets dried and extracted, and the leaf is what sits in our capsules. Soursop is a commercial fruiting crop, so the trees are overwhelmingly cultivated — orchards and smallholdings — rather than gathered from the wild. Our soursop extract is certified organic.

Other common names: Graviola, guanábana, corossol, custard apple (loosely)
Part used in our capsules: Leaf
Part used in our drops: Full-spectrum soursop
Where it grows: Tropical and subtropical regions: the Americas, the Caribbean, West Africa, South and South-East Asia
Wild or cultivated: Predominantly cultivated

02 What's in our product

Understanding "30:1"

Both products use a 30:1 extract. The ratio is arithmetic, not marketing shorthand: 30 kilograms of dried raw soursop material processed down to 1 kilogram of finished extract powder. So 1 mg of extract comes from 30 mg of starting material.

450 mg of 30:1 extract × 30 = 13,500 mg. That is where the label figure comes from.

You are not swallowing 13,500 mg. You are swallowing 450 mg of a concentrate made from that quantity of dried plant material.

One consequence matters for safety. A concentrated extract is not the same thing as eating the fruit or drinking a leaf infusion — concentration changes the amount of every constituent, including the ones covered in the safety section below.

Soursop Capsules

Extract: Organic soursop (graviola) leaf extract, 30:1
Per capsule: 450 mg of extract, equivalent to 13,500 mg of soursop
Serving: One capsule
Capsule shell: Vegan capsule shell
Other ingredients: No synthetic fillers
Allergens: Free from common allergens
Suitable for vegans: Yes
GMO status: Non-GMO ingredients
Count: 60 capsules
How long a bottle lasts: Two months at one capsule daily
Manufacture: Made in a facility adhering to Good Manufacturing Practice (GMP)

Soursop Liquid Drops

Extract: Soursop (full spectrum), 30:1
Per 2 ml serving: 600 mg of extract, equivalent to 18,000 mg of soursop
Other ingredients: Vitamin C; green tea extract; vegetable glycerine and purified water base
Alcohol: Alcohol-free
Suitable for vegans: Plant-based
GMO status: Natural, non-GMO ingredients
Bottle size: 60 ml dropper bottle
How long a bottle lasts: One month at 2 ml daily (30 servings)

The two formats are not equivalent doses. Drops deliver 600 mg of extract per serving, capsules 450 mg, and the drops also carry green tea extract and vitamin C that the capsules do not. Take one format or the other, not both. Read the pack for the full, current ingredient list — the label on the product you receive is the authoritative version.

03 How to take it

Capsules

One capsule daily, preferably with a meal and a glass of water. Do not exceed the recommended amount.

Drops

Squeeze 2 ml into water, juice or coffee and stir well. Straight into the mouth works too. Use the graduated dropper supplied so the amount is the same each time. Do not exceed the recommended amount.

Timing

There is no established best time of day. Pick a time you will actually remember, and keep to it. Do not double up if you miss a day.

Storage

Cool, dry place, out of direct sunlight, both formats. Replace the dropper cap firmly after each use. Keep out of the sight and reach of children. Do not use after the best-before date on the pack.

04 Taste and format

Capsules bypass taste almost entirely. The shell is neutral and swallows easily with water. Open one and you meet the extract directly: a fine plant powder, dry and leafy on the nose, bitter and astringent on the tongue. Concentrated leaf extracts generally are. The capsule format exists precisely so you do not have to meet it.

Drops are taken by mouth, so taste is part of the deal. The base is vegetable glycerine and purified water — mildly sweet, slightly viscous, and it takes the edge off the extract. Green tea extract adds astringency. Taken straight the flavour is noticeable but brief; diluted in water, juice or coffee it recedes considerably, and a drink with some flavour of its own carries it better than plain water does.

Choosing between them is mostly practical. Capsules are fixed-dose and portable, with no measuring and no taste. Drops suit anyone who struggles with tablets, and they go into a drink you were having anyway. Note the difference in strength and additional ingredients set out above.

05 Safety, cautions and interactions

Soursop needs a fuller safety discussion than most botanicals we sell. Please read this section properly before deciding whether it is right for you.

The status of the evidence

There is no European Union herbal monograph for Annona muricata, and it is not a registered traditional herbal medicine in the UK. No regulator-agreed dose, then. No agreed maximum duration of use, and no official posology to fall back on. Human safety data on concentrated soursop supplements is limited. Where we say the data is thin below, that is a statement of fact rather than reassurance.

Annonacin and atypical parkinsonism

This is the most material caution and we will not bury it.

Annona muricata naturally contains a class of compounds called annonaceous acetogenins. The most abundant is annonacin. Acetogenins act as inhibitors of complex I of the mitochondrial respiratory chain — the machinery cells use to produce energy.

Observational studies in Guadeloupe in the French Caribbean, and later in New Caledonia, reported an unusually high number of cases of an atypical parkinsonian syndrome: a movement disorder that, unlike ordinary Parkinson's disease, did not respond to levodopa. Those cases were statistically associated with habitual, long-term consumption of soursop fruit and of infusions made from the leaves. Post-mortem examination in affected patients found accumulation of tau protein in the midbrain.

Supporting laboratory work exists. In rats given annonacin intravenously over 28 days, annonacin accumulated in brain tissue, brain ATP levels fell, and abnormalities appeared in the basal ganglia. Mice given soursop fruit juice orally for a year showed increased numbers of neurons carrying phosphorylated tau. In cultured cells, annonacin promoted the death of dopaminergic neurons, and marketed supplement preparations containing leaves and stems showed a high degree of toxicity to human midbrain cells.

Causation in humans is not proven, and the researchers themselves say so — it is difficult to prove. The European Food Safety Authority (EFSA) reviewed all of this in its 2020 risk assessment on the use of Annona muricata in food supplements and concluded that substantial uncertainties exist regarding safe use, and that the data provide strong indications of neurotoxic potential in certain A. muricata preparations.

EFSA stated that the available evidence, particularly the shortage of long-term studies, does not allow a safe intake level to be established.

Annona muricata is listed in EFSA's Compendium of botanicals reported to contain naturally occurring substances of possible concern for human health.

The French food safety agency (AFSSA, now ANSES) reached a related position in a 2010 opinion. It could not set quantitative consumption recommendations, but advised that soursop preparations warrant particular attention regarding the extraction of toxic compounds, and that prolonged courses of leaves and concentrated extracts should be avoided.

What this means in practice. Do not take soursop continuously over long periods, and do not take more than the amount on the label. Regular, high, long-term intake is not advised. If you choose to use it, use it for short, defined periods with breaks in between rather than indefinitely. Do not combine our capsules and drops, and do not take them alongside other Annona-containing products, teas or juices.

Who should not take it

Anyone who is pregnant or breastfeeding. Do not take soursop supplements. There is no adequate safety data for this group.
Anyone with Parkinson's disease, atypical parkinsonism, or another movement or neurodegenerative disorder — or a family history of one — should not take it without first speaking to their doctor.
Anyone taking Parkinson's medication, including levodopa and related dopaminergic drugs, should not take it without medical advice.
Children and anyone under 18. Not suitable.
Anyone with a known allergy or sensitivity to soursop or other Annonaceae fruits.
Anyone with liver or kidney problems should speak to their doctor first. Data on concentrated soursop extracts in this group is limited.

Medicine interactions

Speak to your GP or pharmacist before taking soursop if you take any prescribed medicine. The following are specifically flagged in the herb–drug interaction literature, including the Memorial Sloan Kettering About Herbs database:

Blood pressure medicines. Graviola is flagged as potentially having additive effects with antihypertensive medication. Do not combine without checking first.
Diabetes medicines. Graviola is flagged as potentially having additive effects with glucose-lowering medication. Do not combine without checking first. If you monitor your blood glucose, be aware that readings may be affected.
Parkinson's medication. Covered above. Do not combine without medical advice.
Any medicine at all, and any ongoing medical treatment. The EFSA review specifically identified the absence of drug–supplement interaction studies for A. muricata as a data gap. Absence of a documented interaction is not evidence that none exists.

The drops additionally contain green tea extract and vitamin C. If you avoid green tea, limit caffeine, or take a medicine known to interact with green tea, check the label and speak to your pharmacist before using the drops.

Tests, scans and surgery

Imaging. Graviola can affect the results of positron emission tomography (PET) scans. Tell your clinical team you are taking it, and follow their instructions about stopping beforehand.
Blood tests. It may affect measured blood glucose and blood pressure readings. Mention it to whoever is interpreting the results.
Surgery. As a general precaution with botanical supplements, stop taking soursop at least two weeks before any planned operation, and tell your surgeon and anaesthetist that you have been taking it.

When to stop and seek advice

Stop taking it and speak to your doctor promptly if you notice tremor, muscle stiffness, slowed movement, changes in balance or walking, or any other unexplained neurological symptom. Stop and seek advice if you develop a rash, swelling, breathing difficulty or any other sign of an allergic reaction, or if you feel unwell after taking it.

When to speak to a pharmacist

A community pharmacist is the easiest first port of call and you do not need an appointment. Speak to one if you take any regular medication, if you have an ongoing health condition, if you are unsure whether soursop is compatible with something else you take, or if you are simply not certain whether it is appropriate for you. Take the product pack, or a photograph of the label, with you.

Never stop or change a prescribed medicine in order to take a food supplement, and never use a food supplement in place of medical treatment.

Our soursop products

Two formats of the same 30:1 organic soursop extract. Read the safety section above before ordering, and speak to your doctor or pharmacist if anything in it applies to you.

Soursop Capsules — 450 mg of 30:1 organic soursop leaf extract per capsule, 60 vegan capsules, a two-month supply at one a day.
Soursop Liquid Drops — 600 mg of 30:1 soursop extract per 2 ml serving, 60 ml alcohol-free dropper bottle, a one-month supply.

UK Standard delivery is free on orders of £28 or more, otherwise £2.99. UK Express is £5.99, and free on orders of £48 or more. Orders are dispatched within 1–2 business days and delivery typically takes 1–4 business days, by Royal Mail or Amazon Logistics. You have 30 days from receipt to request a return; the item must be unopened, untampered, in its original packaging and accompanied by proof of purchase. Email hello@probotanics.co.uk to start a return — items sent back without requesting a return first are not accepted.

This is a food supplement, not a medicine. It is not intended to diagnose, treat, cure or prevent any medical condition, and it is not a substitute for a varied diet and a healthy lifestyle. If you are pregnant, breastfeeding, taking any medication or under medical care, speak to your doctor or pharmacist before use.