Alpha-casozepine
Benzodiazepine-like decapeptide
Also known as: Zylkene ยท Alpha casozepine
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
๐ NA โ North America๐ EU โ Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Stress and anxiety reduction | 15 mg/kg | PO | q24h | Start before exposure to stressor | ๐ EU |
- Stress and anxiety reduction: Evidence for efficacy is considered weak.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Stress and anxiety reduction | 15 mg/kg | PO | q24h | Start before exposure to stressor | ๐ EU |
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Alpha-casozepine is a benzodiazepine-like decapeptide derived from milk protein (casein). It is used as a calming nutraceutical to reduce the impact of a range of stressors in dogs and cats, including unusual and unpredictable situations, kenneling, or changes to the normal environment (such as the arrival of a new baby).
โClinical Warning:โ A recent online review of the literature concluded that the evidence in support of the use of ฮฑ-casozepine for the management of anxiety is weak. It is best utilized as an adjunct to environmental management and behavioral modification rather than a standalone treatment.
Mechanism of action
Acts as a GABA-B agonist. It mimics the properties of benzodiazepines by binding to GABA receptors in the central nervous system โ promoting inhibitory neurotransmission โ resulting in a mild calming or anxiolytic effect without significant sedation or muscle relaxation.
Safety & warnings
Contraindications
- None reported
Adverse effects
- Diarrhea (occasional)
Precautions
Normal precautions apply.
โClinical Pearl:โ Dosing should ideally start several days before exposure to the anticipated stressor to achieve maximum efficacy.
Monitoring
- Clinical response to the stressor
- Fecal consistency (monitor for diarrhea)
Pharmacokinetics
Half-life
Absorption
Absorbed from the gastrointestinal tract after oral administration.
Distribution
Crosses the blood-brain barrier to act on GABA receptors.
Metabolism
Metabolized via normal peptide degradation pathways.
Elimination
Excreted primarily via urine and feces.
Overdose
No specific overdosage information is provided. As a milk-derived nutraceutical, it has a very wide margin of safety. Massive overdose may lead to gastrointestinal upset (diarrhea).
Available products
Formulations
- 75 mg capsule
- 225 mg capsule
- 450 mg capsule
- Combination nutraceutical formulations
Veterinary
- Zylkene 75 mg capsules
- Zylkene 225 mg capsules
- Zylkene 450 mg capsules
Regulatory status
Available on general sale as a complementary feed/nutraceutical.
Available on general sale.
No regulatory data for: ๐บ๐ธ US ยท ๐ญ๐ฐ HK ยท ๐น๐ผ TW ยท ๐ฏ๐ต JP ยท ๐ฐ๐ท KR ยท ๐ฆ๐บ AU
Storage & stability
Store in a cool, dry place away from direct sunlight.
Client information
Alpha-casozepine is a natural, milk-derived supplement used to help pets cope with stressful situations (e.g., fireworks, vet visits, kenneling, or a new baby in the home).
- โTiming is key:โ Start giving the supplement a few days before the expected stressful event for the best results.
- โAdministration:โ The capsules can be given whole or opened and the powder mixed with your pet's food or a treat.
- โSide effects:โ It is very safe, though mild diarrhea occurs occasionally.
- โExpectations:โ It is not a strong sedative. It works best when combined with behavioral training and environmental management.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerโs current label.