Herbal medicine: what the research says

Some herbs have evidence, such as St John's wort for mild low mood, but many uses rest on tradition, and herbs can clash with medicines.

What a session is

A herbalist or naturopath asks about your health and lifestyle and may suggest remedies made from plants, such as teas, tinctures or capsules. On Sissoo, sessions include naturopathy consultations online or in person.

What the research says

• Back, neck and muscle tension: Cayenne cream or plasters eased low back pain for up to six weeks in studies. Other herbs have weaker evidence; long-term use is untested. Some evidence it may help · Cochrane, 2014 · NCCIH, 2020
• Low mood: Studies suggest St John's wort may help mild or moderate low mood, but it weakens many medicines. See a GP if low mood lasts. Limited evidence · NCCIH, 2025
• Menopause: Black cohosh may ease hot flushes, the EU regulator says, but reviews disagree. It has rarely been linked to liver problems. Limited evidence · EMA (EU medicines regulator), 2018 · NCCIH, 2024 · Cochrane, 2012
• Sleep: Valerian studies disagree; US sleep doctors advise against it for long-term poor sleep. Passion flower and lemon balm: traditional use only, not shown in studies. Limited evidence · NCCIH, 2025 · EMA (EU medicines regulator), 2016 · EMA (EU medicines regulator), 2016
• Stress: EU regulators accept lavender oil, passion flower and lemon balm for mild stress on traditional use only; studies were too small to show an effect. Limited evidence · EMA (EU medicines regulator), 2014 · EMA (EU medicines regulator), 2016 · MHRA (GOV.UK), 2024
• Worry and anxiety: Small studies of lavender oil capsules and chamomile hint at less anxiety, with no firm answers. Kava has been linked to serious liver harm. Limited evidence · NCCIH, 2024 · NCCIH, 2025
• Grief: Not studied for grief in the sources we use. No good evidence yet

More on each need: A relaxed body · Lift your mood · Menopause wellbeing · Sleep better · Handle stress better · Feel calmer · Grief and loss

Is it safe?

Herbs can interact with medicines such as antidepressants, blood thinners, statins and the contraceptive pill; St John's wort weakens many medicines. The NHS advises against herbal medicines for children, if you're expecting a baby or breastfeeding, or have liver or kidney problems. In the UK, look for the THR mark, tell your doctor what you take and don't stop prescribed medicine. NHS, 2026 · NCCIH, 2019 · NCCIH, 2025

Sessions on Sissoo complement medical care and never replace it. Please don’t stop or change any treatment without talking to your doctor. If you feel very low or think about ending your life, call your local emergency number now.

Sessions on Sissoo

Sissoo earns a commission when you book. This never changes the ratings on this page.

Find a herbalism consultation →

Checked 22 October 2026. Next check by April 2027. How we rate the evidence.