Herbs for anxiety and stress: what has evidence and what to watch for
Some herbs used for anxiety and stress have surprisingly strong evidence. But they can interact with medicines; St John’s wort in particular weakens many drugs.
In short
The strongest evidence for anxiety is for lavender oil capsules, and for mild to moderate depression it is for St John’s wort. But St John’s wort interacts with many medicines; talk to a doctor before using it.
The plants, strongest evidence first
Lavender Lavandula angustifolia
Standardised oral lavender oil capsules beat placebo for anxiety disorder in several controlled trials.
St John’s wort Hypericum perforatum
According to a Cochrane review, standardised extracts beat placebo in mild to moderate depression. But it weakens many medicines, including the contraceptive pill and blood thinners.
Lemon balm Melissa officinalis
Traditional use in mild stress is recognised; small studies report improvements in anxiety.
Valerian Valeriana officinalis
Recognised in Europe for mild nervous tension; results are mixed.
Chamomile Matricaria chamomilla
Small studies on anxiety are positive.
Ashwagandha Withania somnifera
Small, short trials report lower stress scores. Liver injury cases have been reported; it should not be used in pregnancy.