Herb-Drug Interactions: Starflower oil

Borago officinalis L. (Boraginaceae)

Synonym(s) and related species

Beebread, Bee plant, Borage, Borage oil, Burrage.


Refined Borage Oil (British Ph 2009); Refined Borage (Starflower) Oil (European Ph, 6th ed., 2008 and Supplements 6.1, 6.2, 6.3 and 6.4).


The oil from starflower seeds contains the essential fatty acids of the omega-6 series, linoleic acid (about 30 to 41%) and gamolenic acid (gamma-linolenic acid, about 17 to 27%). Other fatty acids include oleic acid, alpha-linolenic acid, palmitic acid and stearic acid.

Starflower leaves contain potentially hepatotoxic pyrrolizidine alkaloids including lycopsamine, intermedine and their derivatives.

Use and indications

Starflower is thought to possess diuretic, expectorant and anti-inflammatory properties. The main use of starflower comes from its seed oil, which contains none of the hepatotoxic pyrrolizidine alkaloids found in the leaves. The oil is used as an alternative to evening primrose oil, as a source of gamolenic acid.

Infusions of the leaves have traditionally been used for fevers and coughs but it is not recommended that starflower leaves are taken internally, especially if fresh, because they contain small amounts of the hepatotoxic pyrrolizidine alkaloids. The leaves have also been used as an emollient poultice.


No relevant pharmacokinetic data found, but see evening primrose oil for information on the pharmacokinetics of cis-linoleic acid.

Interactions overview

Evening primrose oil contains linoleic acid and gamolenic acid, which are the main active constituents implicated in its interactions. Starflower oil also contains these constituents, and is therefore expected to interact in the same way. See evening primrose oil.