Blackthorn is a shrub. The berry and dried flower are used as medicine.

People use blackthorn for the common cold, cough, fatigue, constipation, and other conditions , but there is no good scientific evidence to support these uses.

In foods, blackthorn is used in herbal teas, syrups, wines, and liqueurs.
When taken by mouth: Blackthorn flower is POSSIBLY SAFE when taken by mouth short-term. One to two cups per day of tea prepared with 1-2 grams of blackthorn flowers have been used with apparent safety. But blackthorn is POSSIBLY UNSAFE when the seeds or fresh flowers are used in large doses or long-term. These parts of the plant contain poisonous chemicals.

When applied to the skin: Blackthorn berries are POSSIBLY SAFE when applied to the skin, short-term. Traditionally, preparations containing 2-4 grams of blackberry fruit have been applied to the skin with apparent safety.

Special Precautions & Warnings:

Pregnancy: Blackthorn seeds and fresh flowers are POSSIBLY UNSAFE for pregnant women because they contain chemicals that can cause birth defects. These chemicals can also cause toxicity.

Breast-feeding: There isn't enough reliable information to know if blackthorn is safe to use when breast-feeding. Stay on the safe side and avoid use


NatMed Pro rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
Likely effective Effectiveness definitions
Possibly effective Effectiveness definitions
Likely ineffective Effectiveness definitions
Possibly ineffective Effectiveness definitions
Insufficient evidence Effectiveness definitions
  • Common cold.
  • Constipation.
  • Cough.
  • Fatigue.
  • Indigestion (dyspepsia).
  • Skin irritation.
  • Sore mouth or throat.
  • Stomach pain.
  • Infections of the kidney, bladder or urethra (urinary tract infections or UTIs).
  • Other conditions.
More evidence is needed to rate the effectiveness of blackthorn for these uses.

Dosing & administration

The appropriate dose of blackthorn depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for blackthorn. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

Interactions with pharmaceuticals

It is not known if Blackthorn interacts with any medicines. Before taking Blackthorn, talk with your healthcare professional if you take any medications.

Interactions with herbs & supplements

There are no known interactions with herbs and supplements.

Interactions with foods

There are no known interactions with foods.


There isn't enough information available to know how blackthorn might work. has licensed monographs from TRC Healthcare.
This monograph was last reviewed on 31/05/2023 10:00:00 and last updated on 25/11/2020 23:16:38. Monographs are reviewed and/or updated multiple times per month and at least once per year.
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