Ashwagandha for Dogs: Evidence, Mechanisms, and Limitations
By Pawsd Editorial
Last reviewed
Ashwagandha root extract (Withania somnifera) has been studied in geriatric dogs via two small RCTs. What the trials measured, what they found, and where the evidence falls short.
Published
Apr 14, 2026
Updated
Apr 14, 2026
References
4 selected
What ashwagandha is and how it is classified
Ashwagandha (Withania somnifera) is a plant in the nightshade family (Solanaceae) used for centuries in Ayurvedic practice. The root and root extract — referred to in the veterinary literature as ARE (ashwagandha root extract) — are the forms most commonly studied in dogs. As a botanical, ashwagandha belongs to the broader category of adaptogens: plant compounds proposed to support the body's ability to regulate physiological stress responses.
A narrative review of adaptogens in humans and dogs notes that plant substances in this class have been described as supporting the regulation of cortisol levels, neurotransmission, and neuroplasticity, though the review acknowledges that research in dogs specifically remains limited and that further study is needed to confirm effectiveness and safety in animal populations (Kępińska-Pacelik and Biel, 2025; DOI: 10.3390/app15105402). The same review observes that dogs, like humans, respond to plant compounds, which frames the scientific interest in extrapolating findings from human adaptogen research to veterinary practice, while also highlighting the evidence gap.
Ashwagandha's proposed mechanisms in the stress-axis context center on modulating cortisol, a glucocorticoid that rises in response to physiological and psychological stressors. Controlled dog trials have tested whether oral ARE supplementation shifts measurable cortisol and related biomarkers — work summarized in the sections below.
Key takeaway
Ashwagandha root extract (ARE) is classified as an adaptogen. Narrative review characterizes adaptogens as supporting cortisol regulation and neurotransmission, but acknowledges a lack of data on their effects in dogs specifically.
Cortisol and stress-axis findings in dogs
The most directly relevant dog-specific evidence comes from a randomized, double-blind, placebo-controlled trial (n=20 healthy geriatric dogs) by Bharani et al. (2024; PMCID: PMC11288135), which administered ARE orally at 15 mg/kg daily for 60 days. The trial found that serum cortisol levels were significantly lower in the ARE-treated group at day 60 compared to placebo, a directionally meaningful result given cortisol's role as a primary biochemical marker of physiological stress (Bharani et al., 2024; PMCID: PMC11288135).
Several contextual limitations apply to this finding. The study enrolled healthy geriatric dogs, not dogs with documented anxiety or stress disorders. The sample was small (n=20) and the population was geriatric, which limits generalizability to younger or clinically anxious dogs. No behavioral outcomes — such as observed anxiety signs or behavioral rating scales — were reported alongside the cortisol measurement.
The same trial reported that leukocyte count decreased significantly after 60 days of ARE treatment (p < 0.05), which the authors interpreted as potentially indicating reduced systemic inflammation; however, leukocyte count is an indirect proxy and the interpretation is speculative without clinical confirmation (Bharani et al., 2024; PMCID: PMC11288135). Serum glucose levels were also significantly reduced in ARE-treated dogs at both 30 and 60 days compared to placebo (Bharani et al., 2024; PMCID: PMC11288135), a finding the authors noted but did not attribute to a specific mechanism within the bounds of the study.
No published dog trial has examined whether ARE supplementation reduces behavioral anxiety signs, owner-rated anxiety scores, or cortisol responses to acute stressors. The cortisol reduction finding is from a resting, healthy-animal baseline and should not be extrapolated to claim anxiolytic efficacy in clinical presentations.
Key takeaway
In a small RCT of healthy geriatric dogs (n=20), daily ARE at 15 mg/kg significantly reduced serum cortisol at day 60 compared to placebo. The study enrolled healthy animals without anxiety diagnoses and reported no behavioral outcomes alongside the cortisol measure.
Antioxidant and inflammation markers
The Bharani et al. (2024; PMCID: PMC11288135) RCT measured a panel of oxidative stress and inflammatory biomarkers alongside the cortisol data. Taken together, the antioxidant findings were consistently directional:
Antioxidant enzymes
Superoxide dismutase (SOD) and catalase levels were both significantly elevated in ARE-treated dogs at day 30 and day 60 compared to placebo (Bharani et al., 2024; PMCID: PMC11288135). Glutathione (GSH) levels were similarly enhanced in the ARE-treated group at both time points (Bharani et al., 2024; PMCID: PMC11288135). These three enzymes are components of the primary antioxidant defense system; their elevation suggests that ARE may upregulate endogenous antioxidant capacity in geriatric dogs, though whether this translates to clinically meaningful outcomes is not established from this trial alone.
Lipid peroxidation marker
Malondialdehyde (MDA), a marker of lipid peroxidation and oxidative damage, was significantly reduced in ARE-treated dogs at day 30 compared to placebo (Bharani et al., 2024; PMCID: PMC11288135). The day-60 MDA passage contains an apparent typographic error in the source document, and only the day-30 finding can be fully confirmed from the cited text.
Pro-inflammatory cytokines
IFN-γ levels were significantly lower in the ARE-treated group at day 30 (p < 0.01) and day 60 (p < 0.001) compared to placebo (Bharani et al., 2024; PMCID: PMC11288135). TNF-α showed a similar pattern — significant reduction in ARE-treated dogs at day 30 and day 60 versus placebo (Bharani et al., 2024; PMCID: PMC11288135). IFN-γ and TNF-α have pro-inflammatory roles; their reduction may reflect immunomodulatory activity, though this interpretation requires caution in the absence of clinical outcome data. NF-κB showed a trend toward decline in ARE-treated dogs but the change was not statistically significant (Bharani et al., 2024; PMCID: PMC11288135).
Liver and kidney function markers
AST and ALT were significantly lower in ARE-treated dogs at day 30 and day 60 compared to placebo (Bharani et al., 2024; PMCID: PMC11288135). Serum creatinine was significantly reduced at both time points (Bharani et al., 2024; PMCID: PMC11288135), and blood urea nitrogen (BUN) was similarly lower in the ARE-treated group at day 30 and day 60 (Bharani et al., 2024; PMCID: PMC11288135). The clinical significance of these reductions — whether they reflect improved organ function or an artifact of the geriatric population's baseline physiology — requires larger studies to interpret.
Key takeaway
The Bharani et al. (2024) RCT found consistent directional improvements across antioxidant enzymes (SOD, catalase, GSH), a lipid peroxidation marker (MDA at day 30), and pro-inflammatory cytokines (IFN-γ, TNF-α) in geriatric dogs. None of these endpoints were behavioral, and clinical translation remains unestablished.
Gut health and microbiome findings
A second RCT from the same research group (Bharani et al., 2025; PMCID: PMC11794502) investigated ARE's effects on gut parameters in a separate cohort of 12 healthy geriatric beagle dogs over 60 days, using a randomized, double-blind, placebo-controlled design. The primary focus was gastrointestinal physiology.
Key findings from this trial include:
- Short-chain fatty acids (SCFAs): Total faecal SCFA levels were significantly higher in ARE-treated dogs after 60 days compared to placebo (Bharani et al., 2025; PMCID: PMC11794502). Propionic acid — one SCFA constituent — was specifically higher in the ARE group at day 60 (p < 0.01) (Bharani et al., 2025; PMCID: PMC11794502). SCFAs are produced by gut bacteria during fermentation and are associated with intestinal health, though their direct relevance to anxiety or stress is not established in this trial.
- Faecal score: The faecal score — a measure of stool quality — was significantly lower (improved) in ARE-treated dogs at day 30 and day 60 compared to placebo (Bharani et al., 2025; PMCID: PMC11794502).
- Plasma L-citrulline: Plasma L-citrulline was significantly higher in ARE-treated dogs after 60 days (Bharani et al., 2025; PMCID: PMC11794502). L-citrulline is a marker of intestinal function and enterocyte health.
- Haematological endpoints: RBC counts were significantly higher in ARE-treated dogs at day 60 (p < 0.01), and haemoglobin levels were higher at both 30 and 60 days (p < 0.001 vs. placebo) (Bharani et al., 2025; PMCID: PMC11794502). ALT and AST were significantly lower in the ARE-treated group at day 30 and day 60 (Bharani et al., 2025; PMCID: PMC11794502), replicating the liver-enzyme direction observed in the 2024 trial.
- Null findings: ARE did not significantly alter faecal pH, plasma lactate, or intestinal-type alkaline phosphatase (I-ALP) levels. Glucose, urea, and creatinine were also unaltered, suggesting no negative renal effects from ARE in this cohort (Bharani et al., 2025; PMCID: PMC11794502).
The 2025 trial enrolled healthy research beagles only (n=12), which limits generalizability to mixed-breed pet dog populations and to dogs with gastrointestinal disease.
Key takeaway
In a 60-day RCT of 12 healthy geriatric beagles, ARE supplementation was associated with higher total SCFAs, improved stool quality, higher L-citrulline, and replicated liver-enzyme improvements from the 2024 trial. No anxiety or behavioral endpoints were measured.
Multi-herb blends containing Withania somnifera
Beyond isolated ARE studies, one small trial has examined a multi-ingredient supplement containing ashwagandha alongside other botanicals. Ciarcia et al. (2025; PMCID: PMC12696704) conducted an uncontrolled case series of 7 senior dogs receiving a blend of Passiflora incarnata, Withania somnifera (ashwagandha), and Taraxacum officinale (dandelion root). Key findings included:
- Inflammatory markers: C-reactive protein (CRP) and serum IL-6 were statistically lower at 20 and 40 days of supplementation compared to baseline (Ciarcia et al., 2025; PMCID: PMC12696704). IL-10 also decreased significantly at both time points, though the clinical direction of this change is ambiguous without a control group (Ciarcia et al., 2025; PMCID: PMC12696704).
- Oxidative stress: Total antioxidant capacity (TAC) increased significantly after 40 days, while MDA — a lipid peroxidation marker — was significantly reduced by 40 days (Ciarcia et al., 2025; PMCID: PMC12696704). A marker of DNA oxidative damage (8OHdG) also decreased significantly by day 40 (Ciarcia et al., 2025; PMCID: PMC12696704).
- Gut microbiota: No statistically significant changes in alpha or beta diversity of the gut microbiota were detected over the 40-day period (Ciarcia et al., 2025; PMCID: PMC12696704).
- Safety markers: Glucose, creatinine, BUN, SDMA, haemoglobin reticulocyte, and albumin remained within normal ranges throughout the trial, with no significant pre-post differences (Ciarcia et al., 2025; PMCID: PMC12696704).
The uncontrolled design means that causal attribution to any ingredient — including ashwagandha — is not possible from this study. The blend's effects cannot be disentangled across its three botanical components. The sample of 7 dogs is substantially underpowered for reliable effect estimation.
Key takeaway
A 7-dog uncontrolled case series found directional improvements in inflammation and oxidative stress markers with a Passiflora/Withania/Taraxacum blend in senior dogs. The design cannot isolate ashwagandha's contribution or establish causation.
Evidence gaps and limitations
The dog-specific evidence base for ashwagandha as of 2026 rests on two small RCTs from the same research group (Bharani et al., 2024; Bharani et al., 2025), one uncontrolled case series (Ciarcia et al., 2025), and a narrative review that explicitly acknowledges a lack of data on adaptogens in dogs (Kępińska-Pacelik and Biel, 2025). The following gaps are clinically important:
No behavioral or anxiety endpoints
Neither Bharani et al. (2024) nor Bharani et al. (2025) included behavioral measures, anxiety rating scales, or owner-reported behavioral outcomes. The cortisol reduction finding is from resting, healthy animals and cannot be extrapolated to predict whether ARE would reduce anxiety signs in dogs with separation distress, noise phobia, or generalized anxiety.
Healthy geriatric-only samples
Both RCTs enrolled healthy geriatric dogs — not dogs presenting with anxiety, behavioral disorders, or disease. The populations most likely to be offered ashwagandha by pet owners (anxious dogs of varied ages) have not been studied in controlled trials.
Small samples and single-group replication
n=20 (Bharani 2024) and n=12 (Bharani 2025) are below the thresholds typically required for reliable effect estimation or safety characterization. Both trials originate from the same group, meaning independent replication is absent.
Dose, form, and duration unknowns
The trials used 15 mg/kg daily oral ARE for 60 days in geriatric dogs. Whether this dose, form, or duration applies to other populations — or whether different formulations produce comparable bioavailability — is not established in published dog research.
Adaptogen research gap in dogs
The broader adaptogen literature in dogs remains sparse. A narrative review covering adaptogens in both humans and dogs notes that research on adaptogens in humans is considerably more advanced, and that the effectiveness and safety of adaptogens in animal therapy require further research for confirmation (Kępińska-Pacelik and Biel, 2025; DOI: 10.3390/app15105402).
Key takeaway
No dog trial has tested ARE against behavioral anxiety endpoints. Available evidence is limited to two small RCTs in healthy geriatric dogs from one research group, an uncontrolled case series of 7 dogs, and a narrative review that acknowledges the evidence gap in animals.
How this guide connects to the Pawsd knowledge base
This reference covers the published evidence on ashwagandha root extract (Withania somnifera) in dogs: cortisol and stress-axis findings, antioxidant and inflammation markers, gut health endpoints, and the limitations of the available research. Scout, Pawsd's AI wellness advisor, uses this evidence to contextualize questions about herbal calming supplements, situate ashwagandha relative to the broader adaptogen category, and help owners understand what the current dog-specific research does and does not support. The guide is maintained as a living reference and updated as peer-reviewed evidence is published.
Frequently asked questions
What does the dog-specific research on ashwagandha actually show?
Two small randomized controlled trials in healthy geriatric dogs found that daily oral ashwagandha root extract at 15 mg/kg over 60 days was associated with significant reductions in serum cortisol and pro-inflammatory cytokines (TNF-α, IFN-γ), increases in antioxidant enzymes (SOD, catalase, GSH), improvements in liver function markers (AST, ALT), and gut health indicators including total short-chain fatty acids and stool quality. Neither trial measured behavioral outcomes or anxiety signs. Generalizability to anxious dogs of other ages and breeds is limited by the healthy geriatric research populations and small sample sizes.
Has ashwagandha been shown to reduce anxiety in dogs?
No published controlled trial has tested whether ashwagandha reduces behavioral anxiety signs in dogs. The cortisol reduction finding from Bharani et al. (2024; PMCID: PMC11288135) is from healthy, resting geriatric animals and does not constitute evidence of anxiolytic efficacy in a clinical sense. A narrative review of adaptogens in humans and dogs notes that research specific to dogs remains limited and that further study is needed before effectiveness in animal therapy can be confirmed (Kępińska-Pacelik and Biel, 2025; DOI: 10.3390/app15105402).
What does the research on multi-herb blends containing ashwagandha show?
One uncontrolled case series of 7 senior dogs (Ciarcia et al., 2025; PMCID: PMC12696704) tested a blend of Passiflora incarnata, Withania somnifera, and Taraxacum officinale and found directional reductions in CRP, IL-6, and MDA, alongside increases in total antioxidant capacity, compared to baseline. The uncontrolled design — no control group, only 7 dogs — means the findings cannot be causally attributed to any single ingredient, including ashwagandha. The results are hypothesis-generating rather than confirmatory.
What are the key limitations of the existing ashwagandha dog research?
The principal limitations are: both controlled trials enrolled healthy geriatric dogs (not anxious or clinically presenting animals), sample sizes were small (n=20 and n=12), both trials came from a single research group with no independent replication, no behavioral endpoints were included in any controlled trial, and the tested dose (15 mg/kg daily ARE for 60 days) has not been validated for safety or efficacy in other dog populations. Veterinary supervision is warranted before introducing any herbal supplement into a dog's regimen.
Evidence-informed article
Pawsd Knowledge articles are educational and not a substitute for veterinary advice. These pages draw from selected open-access peer-reviewed veterinary research, with full-text sources linked below.
Selected references
Bharani et al. Vet Med Sci. 2024;10(4):e1556. PMCID: PMC11288135. Open-access RCT, n=20 healthy geriatric dogs; evaluated cortisol, antioxidant enzymes, inflammatory cytokines, and organ-function markers after 60 days of daily ARE at 15 mg/kg.
Bharani et al. Front Vet Sci. 2025;11:1491989. PMCID: PMC11794502. Open-access RCT, n=12 healthy geriatric beagles; evaluated short-chain fatty acids, stool quality, L-citrulline, and haematological markers after 60 days of ARE.
Ciarcia et al. Front Vet Sci. 2025;12:1695881. PMCID: PMC12696704. Open-access uncontrolled case series, n=7 senior dogs; evaluated CRP, IL-6, IL-10, TAC, MDA, and gut microbiota diversity over 40 days with a multi-herb blend.
Kępińska-Pacelik J, Biel W. Appl Sci. 2025;15(10):5402. DOI: 10.3390/app15105402. Open-access narrative review of adaptogenic plants — including cortisol regulation, neurotransmission, and neuroplasticity properties — with a section on the current evidence gap in canine populations.
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