Cat Calming Supplements: What Is Available and What Works
Calming supplements are a useful tool in the anxiety management toolkit, but they vary considerably in evidence quality. Here is a clear-eyed overview of what is available in the UK and how they compare.
Alpha-casozepine (Zylkene)
Evidence level: Good
Alpha-casozepine is derived from a hydrolysate of bovine casein, a milk protein. It binds to the same GABA receptors targeted by benzodiazepine anti-anxiety medications, but without the sedative effects. Multiple peer-reviewed studies demonstrate anxiety reduction in cats, making it the most evidence-backed supplement option currently available.
Capsules can be opened and the powder mixed into food. Start one to two days before an anticipated stressful event. For ongoing anxiety, daily use for a minimum of four weeks is recommended. Available from vets and licensed online pet pharmacies.
L-Theanine
Evidence level: Moderate
An amino acid naturally found in green tea. Associated with anxiolytic effects through increased GABA and serotonin activity. Evidence in cats is primarily from owner reports and small studies, but it is generally well-tolerated and safe. Found in several multi-ingredient cat calming supplements available in UK pet shops.
Herbal ingredients: chamomile, valerian, ashwagandha
Evidence level: Limited in cats
These herbal ingredients appear in various cat supplements. Evidence specifically in cats is very limited. They appear safe in the concentrations typically used in pet supplements and may contribute mild calming effects as part of a multi-ingredient formula. Unlikely to make a significant difference as standalone treatments for more than mild anxiety.
B vitamins
Some supplements include B vitamins, particularly thiamine (B1), on the basis that deficiency can contribute to neurological symptoms including anxiety. For cats eating a complete, balanced diet, deficiency is unlikely. Supplementation is generally harmless and is included as a supporting ingredient in some formulas.
Points to bear in mind
- Supplements are not medications. For significant anxiety, they are a support tool, not a primary treatment.
- Give it time. Most supplements need two to four weeks of consistent use to show their full effect. Do not dismiss something after a few days.
- Combine with environmental management. A supplement alongside a well-resourced environment and reduced stressors is far more effective than a supplement alone.
- Natural does not mean safe for all cats. Always check that any supplement is specifically formulated for cats and from a reputable manufacturer.
- Ask your vet before starting any supplement if your cat has a known medical condition or is on other medication.
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Frequently asked questions
What is the most effective calming supplement for cats?
Alpha-casozepine (sold as Zylkene in the UK) has the strongest evidence base among over-the-counter cat calming supplements. For more significant anxiety, your vet can discuss whether prescription medication is appropriate.
How long do cat calming supplements take to work?
Most supplements need two to four weeks of consistent daily use before their full effect is apparent. Some, like alpha-casozepine, can also be used situationally starting one to two days before a known stressor.
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