Educational information, not medical advice — ask your doctor or midwife.
Manna ash is a small tree of southern Europe and western Asia. Cutting the bark makes a sweet sap run out. The dried sap is called manna, and that is the part used.
Manna is sold as pale flakes, lumps, powder or syrup. It tastes sweet. People have used it mainly as a mild laxative, for adults and for children.
The main ingredient is mannitol, a sugar alcohol. Mannitol is a known osmotic laxative in people, so the bowel effect is real. Trials on manna itself are few, and long use in Europe is not proof that it works or that it is safe.
Manna works in the gut, not in the bloodstream. Most of its mannitol is poorly absorbed.
It stays in the bowel and pulls water in. That softens stool and helps it move. This osmotic effect (water drawn into the bowel) is well established for mannitol in people.
The pull of water also stretches the bowel wall a little. That stretch helps trigger the urge to go. This is the same way other sugar-alcohol laxatives work.
Manna also holds small amounts of fraxin and other coumarins. In laboratory work these show antioxidant activity. Whether they do anything useful in the body at the amounts found in manna is not established.
Folk use for coughs rested on the sweet, sticky texture coating the throat. That soothing feel is plausible. There is no good human evidence that manna treats a cough or clears the chest.
You will meet manna in these forms:
- Flake or pipe manna: hardened pale sticks of sap, the top grade.
- Lumps or broken pieces, a lower grade.
- Powder, sometimes in sachets.
- Syrup, often mixed with other mild laxative herbs such as tamarind or senna.
- Capsules and chewable tablets, less common.
- Food use as a sweetener or sweet spread, mainly in Sicily.
Check the label of mixed syrups. Some combine manna with senna or cascara. Those are stimulant laxatives, they act in a different and stronger way, and they carry their own warnings.
Manna has been collected in Sicily for centuries. The Madonie mountains, around Castelbuono and Pollina, are still the main source. Growers score the bark in summer and let the sap harden on the tree.
European pharmacies stocked manna from the late Middle Ages onward. It appeared in national pharmacopoeias into the twentieth century. Apothecaries favoured it as the gentlest laxative, and reached for it with children and older people.
Folk use also covered coughs, sore throats and chest colds, usually as a sweet syrup. The name caused confusion with the manna of the Bible, which is a different thing. Italian names include orniello and albero della manna.
Stop and see a doctor if constipation lasts more than a week, or keeps coming back.
Get medical help the same day if you have:
- Blood in your stool, or black tarry stool - Severe or growing belly pain - A swollen belly with no bowel movement and no wind - Vomiting that will not stop - Unplanned weight loss alongside the constipation
Get emergency help for a rash with swelling of the lips, face or tongue, or any trouble breathing. Also seek urgent care for marked weakness, muscle cramps or an odd heartbeat after days of laxative use, as these can mean low potassium.
In the European Union manna is sold as a food and as a herbal laxative, and in Italy and some other countries as an over-the-counter medicine. In the United States it is sold as a food or supplement, not as an approved drug. Purified mannitol is a permitted food additive in both regions.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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