Mechanism of Action
L-Theanine crosses the blood-brain barrier and modulates several neurotransmitter systems. It increases alpha brain wave activity, associated with a state of calm alertness without drowsiness. It increases levels of GABA, serotonin and dopamine in the brain, neurotransmitters involved in mood regulation and stress response. It also inhibits glutamate binding to NMDA receptors, reducing excitatory neurotransmission during acute stress. These mechanisms produce anxiolytic effects without sedation, distinguishing L-Theanine from pharmacological anxiolytics.
Evidence Summary
L-Theanine has been studied in dogs specifically. A 2015 study published in the Journal of Veterinary Behavior (Araujo et al) found that L-Theanine supplementation significantly reduced anxiety-related signs in dogs during thunder compared to placebo. A product containing L-Theanine has received regulatory authorisation in some markets as a veterinary calming supplement, which requires demonstration of efficacy. Human evidence is also substantial: multiple RCTs demonstrate reduction in stress and anxiety measures with L-Theanine supplementation. The evidence specifically in dogs is limited in volume but the available studies are positive and the mechanism is well established.
In Petz Park Products
Stress and Anxiety for Dogs: L-Theanine 20mg per scoop. Stress and Anxiety for Cats (Australia and UK): L-Theanine 20mg per scoop. The US formulation of Stress and Anxiety for Cats uses Valerian Root Extract instead.
Safety and Considerations
L-Theanine is considered safe for dogs and cats at supplemental doses. It has no known serious adverse effects. It does not cause sedation at supplemental doses. Suitable for puppies over 8 weeks and for long-term daily use.