Question 1

How does Alnus glutinosa work as a medicinal herb?

Accepted Answer

Alnus glutinosa (black alder) bark contains tannins (approximately 10-20%), flavonoids like luteolin, and diarylheptanoids including oregonin and hirsutanonol. The tannins provide astringent effects by binding to proteins in mucous membranes, which helps tighten tissues and reduce inflammation. This astringent action explains its traditional use for sore throats, diarrhea, and skin conditions. The anti-inflammatory properties of luteolin and related compounds may contribute to its febrifuge (fever-reducing) effects. Evidence level: C (limited scientific evidence).

Question 2

Does Alnus glutinosa interact with any medications?

Accepted Answer

Due to its significant tannin content, Alnus glutinosa bark may potentially interfere with the absorption of certain medications when taken simultaneously. Tannins can bind to alkaloids and some drugs, reducing their bioavailability. While specific clinical drug interaction studies are lacking (Evidence level: C), it is advisable to separate the administration of black alder preparations from oral medications by at least 2 hours. Individuals taking prescription medications should consult a healthcare provider before using Alnus glutinosa preparations.

Question 3

What is the recommended dosage of Alnus glutinosa bark?

Accepted Answer

Traditional adult dosage recommendations for Alnus glutinosa include 1-3 grams of dried bark daily, typically prepared as a decoction or infusion. For liquid extracts, 1-2 mL of tincture taken up to three times daily is commonly suggested. Due to limited clinical evidence (Evidence level: C), these dosages are based primarily on traditional use and pharmacopoeial standards. Doses exceeding these recommendations may cause gastrointestinal upset. Always follow product-specific labeling instructions and consult a qualified herbalist or healthcare provider for personalized guidance.

Question 4

Is Alnus glutinosa safe to take during pregnancy?

Accepted Answer

Alnus glutinosa is considered unsafe during pregnancy and should be avoided. The bark contains significant amounts of tannins and other constituents that may stimulate uterine contractions or affect fetal development. Traditional contraindications specifically warn against use in pregnant women, particularly at higher doses. There is insufficient safety data to support use during breastfeeding either. Women who are pregnant, planning pregnancy, or breastfeeding should not use black alder preparations. Evidence level: C based on traditional contraindications and theoretical risks.

Question 5

What is Alnus glutinosa used for medicinally?

Accepted Answer

Alnus glutinosa (black alder) bark has been used traditionally as an astringent and febrifuge for conditions including sore throat, tonsillitis, fever, diarrhea, and various skin conditions. Its astringent properties make it useful for tightening inflamed mucous membranes in the throat and gastrointestinal tract. Externally, it has been applied to wounds, burns, and skin inflammations. Current evidence supporting these uses is limited (Evidence level: C), based primarily on traditional use and in vitro studies rather than clinical trials. More research is needed to confirm efficacy.

Alnus glutinosa

Sources & Citations

Calculate a safe dose of Alnus glutinosa

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Frequently asked questions

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Evidence summary

PubMed sources

Government sources