Some supplements may help reduce anxiety in dogs, though results vary between individuals and the strength of evidence differs by ingredient. The most promising are those that work with the brain's natural calming systems - particularly L-tryptophan and alpha-casozepine, which influence serotonin and GABA pathways respectively (1).
L-tryptophan is a precursor to serotonin, the neurotransmitter involved in mood regulation. Studies show mixed results: some found reduced anxiety-related behaviors in dogs when combined with other calming ingredients, while tryptophan alone produced inconsistent effects. Individual dogs appear to absorb and respond to it differently, and benefits may take several weeks of daily use to become apparent - making it unsuitable for acute anxiety (severe reactions to things like thunderstorms).
Things to keep an eye on
If you try a supplement, keep a simple log noting anxiety triggers, severity, and frequency of anxious behaviours before and after starting. Without this, it's easy to mistake natural fluctuations or wishful thinking for genuine improvements. Many supplements require 4–6 weeks of consistent use before any change becomes noticeable.
How much is right for my dog?
The pet supplement market has inconsistent quality control, and effective amounts from research studies don't always translate to commercial products. Ingredients like B vitamins, taurine, passionflower, and lemon balm are often included in calming formulas based on their effects in other species. Whilst dog-specific evidence is limited, they do share similar mechanical and physiological pathways, making their theoretical use sound.
Supplements can interact with certain medications, so make sure to check with your vet before starting anything new.
References
- Flint HE, Weller JE, Hunt ABG, King T. Treats containing cannabidiol, L-tryptophan and α-casozepine have a mild stress-reducing effect in dogs. Front Vet Sci. 2025;12:1632868. Available from: https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2025.1632868/full
This content is for general information only and does not replace veterinary advice. Supplements and nutritional products are not licensed veterinary medicines. Always speak to your vet before making changes to your dog’s diet, supplements, or care routine.
