Herbal Calming Remedies for Dogs UK 2026: What the Science Actually Says
Valerian, chamomile, passionflower, ashwagandha — but which herbal remedies have real evidence in dogs? We reviewed every published study, ranked 7 herbs by evidence quality, and flag critical drug interactions.
Quick Answer
Ashwagandha and lemon balm have the strongest direct evidence in dogs from properly designed studies. Most traditional calming herbs (valerian, chamomile, passionflower) have surprisingly little direct canine evidence despite widespread use. Only one UK herbal product — Dorwest Scullcap & Valerian — holds VMD authorisation as a licensed veterinary medicine.
The Evidence Gap: What Most Sites Won't Tell You
Here's an uncomfortable truth: most herbal calming products for dogs are recommended based on human studies, rodent models, and tradition — not evidence from actual dogs. We reviewed every published study we could find on herbal remedies specifically tested in dogs, and the results may surprise you.
This guide ranks 7 popular herbs by their actual canine evidence quality, flags critical drug interactions your vet needs to know about, and explains the important difference between a licensed herbal medicine and an unregulated supplement.
The Evidence Table: 7 Herbs Ranked
| Herb | Dog Evidence | Quality | Safety | How It Works |
|---|---|---|---|---|
| Ashwagandha | RCT in 24 dogs (2022) | Moderate | Good | Cortisol modulation |
| Lemon Balm | RCT in 20 beagles (2025) | Moderate | Very good | GABA support |
| Lavender (inhaled) | 2 published studies | Moderate | Good (aromatherapy only) | Olfactory-limbic pathway |
| Passionflower | 1 reported study (2018) | Weak-Moderate | Good | GABA + mild MAO inhibition |
| Skullcap | Cambridge trial (unpublished) | Weak | Moderate | GABA-A receptor binding |
| Valerian | None in dogs | Very weak | Good (wide safety margin) | GABA breakdown inhibition |
| Chamomile | None in dogs | Very weak | Moderate (allergy risk) | Apigenin binds GABA-A |
The Top 3: Herbs With Real Dog Evidence
1. Ashwagandha — The Strongest Evidence
Ashwagandha (Withania somnifera) has the most rigorous direct evidence in dogs. A 2022 randomised, double-blind, placebo-controlled trial (Kaur et al., Journal of Veterinary Behavior) tested KSM-66 ashwagandha root extract at 15 mg/kg bodyweight once daily for 4 weeks in 24 client-owned dogs.
Study Results
- Statistically significant reduction in urine cortisol:creatinine ratio (P = 0.0005)
- Statistically significant reduction in fear and anxiety on the C-BARQ behavioural assessment (P = 0.03)
- Significant reduction in pain severity and pain interference
- No adverse events reported
How it works: Ashwagandha is an adaptogen that modulates cortisol (the stress hormone). Unlike sedative herbs, it helps the body manage stress responses rather than suppressing the nervous system. Effects build over days to weeks of daily use.
Safety: Well-tolerated in studies. Large doses may cause GI upset. Unsafe for pregnant dogs. Consult your vet if your dog has endocrine disorders.
2. Lemon Balm — Outperformed Zylkene in One Study
Lemon balm (Melissa officinalis) has surprisingly strong evidence. A 2025 randomised study in BMC Veterinary Research tested a hydroalcoholic lemon balm extract at 200 mg/kg on 20 healthy beagle dogs exposed to mild stress.
Results showed statistically significant improvements in behavioural scores. Notably, lemon balm outperformed the alpha-casozepine (Zylkene) positive control group in this study — scoring 2.0 vs Zylkene's 0.8 (placebo scored -3.4).
How it works: Contains flavonoids and rosmarinic acid that support GABA activity. Unlike sedative herbs, lemon balm may increase alertness and focus while calming, rather than causing drowsiness.
Safety: Listed by the ASPCA as non-toxic to dogs. Very safe profile. Found in YuCalm (YuMOVE) products.
3. Lavender — But Only as Aromatherapy
Lavender has published evidence, but only for inhaled use — never ingestion. A study published in JAVMA (Wells, 2006) found that 32 dogs exposed to ambient lavender odour spent significantly more time resting and significantly less time moving and vocalising.
Lavender Ingestion Warning
Lavender contains linalool and linalyl acetate, which are toxic to dogs if ingested. Essential oil is significantly more concentrated and dangerous — even a small amount can cause vomiting, diarrhoea, sedation, and potentially seizures. Never allow dogs to ingest lavender essential oil. For diffusion, use only a few drops in water with adequate ventilation, and ensure your dog can leave the room.
The Traditional Herbs: Less Evidence Than You'd Think
Valerian Root
Despite being one of the most widely used calming herbs for dogs, there are no published clinical studies specifically testing valerian's efficacy in dogs. All recommendations are extrapolated from human and rodent studies — and even in humans, systematic reviews have found the evidence inconclusive.
How it works (in theory): Valerenic acid inhibits the enzyme that breaks down GABA, increasing GABA levels. This is the same system targeted by benzodiazepines, but the mechanism hasn't been confirmed to work identically in dogs.
Dosing: No validated dosing studies exist. Commonly cited figures (1-2 mg per pound, 2-3 times daily) are not evidence-based. Anecdotal onset: 30-60 minutes.
Safety: Wide safety margin in other species. Contraindicated in pregnant/nursing dogs and puppies. May cause excessive sedation in some dogs.
Chamomile
Contains apigenin, a flavonoid that binds to GABA-A receptors. However, there are no direct clinical studies in dogs. Evidence is entirely extrapolated from human studies and traditional use.
Safety concern: Allergic reactions possible in dogs sensitive to the Asteraceae/daisy family. Avoid in pregnant dogs. May interact with blood thinners, sedatives, and antidepressants.
Passionflower
Has a unique dual mechanism — GABAergic plus mild monoamine oxidase (MAO) inhibition, gently modulating serotonin and dopamine. One 2018 veterinary study reportedly found reduced anxiety-related behaviours during thunderstorms and separation, but the full citation is difficult to verify independently.
Safety: Generally well-tolerated. Use specifically Passiflora incarnata (not other species). Contraindicated in pregnant dogs. Discontinue 1-2 weeks before surgery.
Skullcap
Contains baicalin and baicalein, which bind directly to the GABA-A receptor. Traditionally paired with valerian — a pharmacologically sensible combination since valerian increases GABA availability while skullcap enhances receptor sensitivity.
A 2022 Cambridge University trial of Dorwest Scullcap & Valerian Tablets found 87% of dog owners reported reduced fireworks anxiety — but this data remains unpublished and was based on owner-reported outcomes (n=46).
UK Herbal Products Compared
| Product | Key Herbs | Regulatory Status | Can Make Health Claims? |
|---|---|---|---|
| Dorwest Scullcap & Valerian | Valerian, skullcap, mistletoe, gentian | VMD-authorised (AVM-GSL) | ✅ Yes — licensed medicine |
| YuCalm (YuMOVE) | Lemon balm, L-theanine, fish protein | Supplement (complementary feed) | ❌ No |
| Pet Remedy | Valerian, vetiver, basil, clary sage | Environmental calming product | ❌ No |
| Pooch & Mutt Calming | Valerian, hemp, turkey (L-tryptophan) | Supplement (complementary feed) | ❌ No |
Licensed vs Supplement: Why It Matters
A VMD-authorised product (like Dorwest) has undergone assessment for quality, safety, and efficacy. It's the only way a product can legally make therapeutic claims for animals in the UK. Most herbal calming products are sold as supplements or complementary feed — they don't need to demonstrate efficacy and cannot legally claim to treat anxiety.
Critical Drug Interactions
This is the most important safety section. If your dog takes any prescription medication, read this before adding herbal supplements.
High-Risk Combinations
Any herb that enhances GABA activity should be used with extreme caution — or avoided entirely — in dogs taking:
- Benzodiazepines (diazepam, alprazolam) — enhanced sedation risk
- Phenobarbital or other anticonvulsants — altered drug levels
- SSRIs (fluoxetine/Reconcile) — additive sedation, possible serotonin issues
- Tricyclic antidepressants (clomipramine/Clomicalm) — enhanced effects
- Trazodone — additive sedation
- Gabapentin — additive sedation
Highest risk: St. John's Wort has a high risk of causing serotonin syndrome when combined with SSRIs. Never combine these.
Specific interactions to note:
- Valerian + sedatives/anaesthetics: Enhanced sedation and loss of coordination. Discontinue before planned anaesthesia.
- Passionflower + SSRIs: Passionflower's mild MAO inhibition is a theoretical concern with serotonergic drugs.
- Chamomile + blood thinners: Contains coumarin compounds that may enhance anticoagulant effects.
How Herbs Compare to Other Options
| Option | Evidence | Best For | UK Status |
|---|---|---|---|
| Prescription SSRIs | Strong | Chronic/severe anxiety | POM-V |
| Sileo | Strong | Acute noise events | POM-V |
| Ashwagandha | Moderate | General stress/fear | Supplement |
| Lemon Balm | Moderate | Mild-moderate stress | Supplement |
| Dorwest S&V | Weak | Noise phobia, travel | AVM-GSL (licensed) |
| Valerian (standalone) | Very weak | Mild situational | Supplement |
No herbal remedy should be considered a substitute for prescription medications in cases of moderate-to-severe anxiety. They may have a role as complementary measures for mild anxiety, or as part of a multimodal approach alongside behaviour modification. See our dog anxiety medication guide for when professional treatment is needed.
Key Caveats for All Herbal Products
- Lack of standardisation: Active compound concentrations can vary significantly between companies and even between batches of the same product.
- Publication bias: Positive results are more likely to be published. Industry-funded studies are common.
- Extrapolation risk: Dog metabolism differs from human metabolism. A herb that works in humans may not work identically in dogs.
- Placebo effect on owners: Many studies rely on owner-reported outcomes, which are susceptible to expectation bias.
- "Natural" does not mean "safe": Many potent toxins are entirely natural. Dosing matters enormously.
Bottom Line
If you want the best-evidenced herbal option, look for products containing ashwagandha or lemon balm. If you want the only VMD-licensed herbal option in the UK, that's Dorwest Scullcap & Valerian. Always tell your vet about any herbal supplements your dog is taking — especially if they're on other medication.
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