St John’s Wort
St John’s Wort (Hypericum perforatum) is a traditional herbal ingredient best known for supporting mood, emotional balance and nervous system function. Its key plant compounds include hypericin and hyperforin, which influence several neurotransmitter pathways involved in mood regulation.
It has a long history of use in European herbal medicine and is commonly found in formulas for mild mood support, stress resilience and emotional wellbeing.
Mood and Emotional Balance
St John’s Wort has been studied primarily for its effects on mood.
Its active compounds influence neurotransmitters including serotonin, dopamine and noradrenaline, all of which play roles in motivation, emotional regulation and the response to stress.
This makes St John’s Wort most relevant in formulas aimed at supporting a balanced mood and emotional resilience rather than providing an immediate calming or sedating effect.
Nervous System Support
The herb also has a broader traditional association with nervous system health.
It may be useful during periods of ongoing emotional strain or low mood, particularly when included as part of a wider approach that also considers sleep, exercise, nutrition and stress management.
Important Medication Interactions
St John’s Wort can significantly affect the way the body processes many medicines by increasing the activity of certain liver enzymes and transport proteins.
It can interact with antidepressants, oral contraceptives, anticoagulants, transplant medicines, some heart medications and many other prescription drugs. It should not be combined with serotonergic antidepressants without professional guidance.
Anyone taking regular medication should check with a doctor, pharmacist or qualified health professional before using St John’s Wort.
St John’s Wort for Pets
St John’s Wort may also appear in some veterinary herbal formulas aimed at nervous system support, stress and emotional balance.
Because it has significant biological activity and can interact with medicines, it should only be used in dogs or cats at appropriate formulated amounts. Pets taking medication or being treated for behavioural or neurological conditions should receive veterinary guidance before products containing St John’s Wort are introduced.
St John’s Wort in O2B Products
At O2B Healthy, St John’s Wort is used in O2B Mind and Body Balance, where it complements herbs such as chaste tree, oats and black cohosh to support mood, emotional balance and a healthy stress response. It is also included topically in O2B Nervine Soother for nervous system and nerve-ending support, and in O2B Anti-Sep+ alongside Mānuka honey and calendula to support the body’s natural skin repair processes.