Лаванда Узколистная

The flowers are used in infusion and oral and inhaled liquid preparations and the essential oil. The essential oil contains flavonoids, linalin (45%), linalool (45%) and small amounts of camphor (1%) and eucalyptol (2%). Properties attributed in traditional use without reliable evidence: antispasmodic, sedative and anxiolytic ^{(Fitoterapia.net, WHO 2007)}. It is often used as an anxiolytic, for local pain relief with topical, oral or inhaled application in aromatherapy.  It is also used in the relief of anxiety during pregnancy ^{(Effati 2014)}, pain during and after childbirth and caesarean section ^{(Sheikhan 2012, Hadi 2011, Habanananda 2004, Cornwell 1995)} and menstrual pain ^{(Ou 2012)}, but there is little evidence of its efficacy.^{(Jones 2011)}

At least one of its constituents, eucalyptol (1,8-cineole) is excreted in milk, conferring a characteristic odor. ^{(Debong 2024 and 2021, Kirsch 2013 and 2012)}

The essential oil has a mild estrogenic and anti-androgenic effect, and may behave as an endocrine disruptor ^{(Fisher 2014)}, so it should not be applied to the breast to prevent the infant from ingesting it. There have been published cases of transient gynecomastia in children after topical application of essential oil in the form of cosmetic products ^{(Diaz 2015, Block 2012, Kemper 2007, Henley 2007)}. 
Consumption of essential oil should be moderate or none during breastfeeding as, although it is in small quantity, eucalyptol is neurotoxic and convulsant.

A moderate consumption of lavender flowers in infusion during breastfeeding would have little or no risk.