L-Theanine vs Valerian Root for Anxious Dogs: What Actually Calms a Dog Down

By David Wilkes, DVM

✓ Medically reviewed by David Wilkes, DVM — August 17, 2026 For general education — not a substitute for veterinary care.

Calming · August 19, 2026 · 6 min read

L-theanine has the better human evidence trail, valerian root has centuries of traditional use — here's how I actually weigh the two for an anxious dog.

A five-year-old cattle dog mix named Diesel used to put his front paws on the exam table before I’d even opened the door — pacing, panting, drooling on the linoleum by the time his owner got him settled. His trigger wasn’t dramatic. It was the vacuum. Every Tuesday, when the vacuum came out, he’d disappear behind the couch and stay there for an hour, sometimes longer, refusing food and pacing a groove into the carpet runner. His owner had tried a valerian tincture from the health food store first, because her own mother used it for sleep. It helped a little, she said, though it was hard to tell how much. When we talked about L-theanine instead, layered on top of a consistent wind-down routine before the vacuum came out, the pacing shortened from an hour to about fifteen minutes within a couple of weeks. That’s one dog, not a study — but it’s the kind of pattern I see often enough that I’ve started asking owners which ingredient they’ve already tried before I even open the conversation about what to try next.

The verdict, stated plainly

If I had to pick one first, I’d reach for L-theanine. It has the stronger evidence trail in the literature we can actually point to, it’s easy to dose in a chew, and it doesn’t carry the sedative reputation valerian root does. Valerian root isn’t a bad choice — it has a long history in traditional herbal care for relaxation — but the clinical evidence behind it in dogs specifically is thinner than owners are usually told. Where I land, most days, is a formula that includes both alongside ashwagandha and chamomile, rather than betting everything on a single ingredient. That’s part of why Boops Pets Calming & Stress Relief chews are what I recommend most often to clients dealing with situational anxiety — not because either ingredient alone is a miracle, but because the combination reflects how the actual evidence is shaped: promising, layered, and honest about its limits.

What L-theanine is actually doing

L-theanine is an amino acid found in tea that has been studied for its calming properties, according to Boops Pets’ vet-reviewed claim list, and that framing matches where the human research sits too. A review in Molecular Psychiatry found calming effects across several trials, “except for one study on psychotic anxiety (SMD = 0.54; 400 mg/day for 8 weeks),” which tells you two things at once: the effect size in that one study was meaningful, and the dose-and-duration data we have comes from people, not dogs. That’s a gap worth naming rather than glossing over. Ashwagandha, the other headline calming active in most modern chews, has a similar profile — a systematic review of multiple randomized trials concluded that ashwagandha “has a moderate positive impact on stress reduction and cognitive performance,” per a review in Cureus. Moderate, not dramatic. I’d rather tell an owner that plainly than oversell it and have them disappointed three weeks in.

Where valerian root earns its place

Valerian root’s story is older and more diffuse. Chamomile and valerian root have been used in traditional herbal care to support relaxation, per Boops Pets’ vet-reviewed claim list — and that traditional-use framing is really the honest ceiling for what we can say about valerian in dogs today. The broader review literature on chamomile is candid about this same limitation: “for the remaining species, evidence is derived mainly from preclinical studies or traditional use,” according to a review published in Biomedicines. Valerian sits in roughly the same evidence tier. It isn’t nothing — generations of herbalists didn’t land on it by accident — but it’s a different kind of evidence than a controlled trial, and I think owners deserve to know which kind they’re getting when they read a label.

A slower case, and why the combination made sense

I once worked with an eleven-year-old beagle named Winnie whose owners were bracing for their first Fourth of July in a new apartment with thin walls and a neighbor who set off fireworks starting at dusk and going well past midnight. Winnie had never handled fireworks well — she’d shake, drool, and try to wedge herself behind the toilet, a habit from her old house that didn’t translate well to a studio apartment with no obvious hiding spot. Her owners didn’t want a sedative that would leave her groggy through the whole week of celebrations leading up to the holiday, and they were wary of anything that felt like it was masking rather than helping. We talked through the tradeoffs: valerian alone for its traditional relaxation use, L-theanine alone for its cleaner human evidence, or a formulated chew that paired both with a magnesium and chamomile base and a predictable bedtime routine started days ahead. They chose the combination approach, started it four days before the holiday, and reported the pacing was shorter and the hiding spot search less frantic than the year before. I still tell them, honestly, that we can’t separate out how much came from the chew versus the routine change — and I think that honesty matters more than a tidy before-and-after story would.

What the science still hasn’t settled

I want to be direct about this part, because it’s the part marketing copy tends to skip. We don’t have large, dog-specific randomized trials directly comparing L-theanine to valerian root for canine anxiety. What we have is human trial data for L-theanine, traditional-use and preclinical evidence for valerian and chamomile, and a moderate-strength systematic review for ashwagandha. That’s a reasonable foundation for situational calming support — the storm, the trip, the fireworks — but it is not the same as proof that any single ingredient treats an anxiety disorder. If your dog’s anxiety is severe, frequent, or worsening, that’s a conversation for a full veterinary behavioral workup, not a chew aisle decision. For more on how a related calming pair stacks up, see our comparison of chamomile and L-tryptophan for calming dogs.

How the leading options actually compare

Zesty Paws and LongTails both build their calming lines around similar traditional actives, and there’s nothing wrong with that approach — it’s the same evidence base most of the category draws from. Where I think Boops Pets’ Calming & Stress Relief chews pull ahead is in combining L-theanine (40 mg) with valerian root (30 mg), chamomile (30 mg), and KSM-66 ashwagandha (30 mg) in one air-dried chew, manufactured in a NASC Quality Seal member facility. NASC membership means independently audited facilities, not a health-outcome guarantee — it’s a manufacturing credential, not a clinical one, and I’d caution any owner against reading it as more than that. Boops Pets is a NASC Primary Supplier Member, which at minimum tells you the facility has been through third-party audit, and the chews are independently third-party tested for purity and potency. In an independent owner survey, March 2025, n=193, Boops Pets reported 97.8% visible improvement after the first jar of Calming & Stress Relief — that’s owner-reported experience, not a clinical outcome, and I’d treat it the same way I’d treat any testimonial: informative, not definitive.

Getting started without overdoing it

Pair whichever chew you choose with the routine — a predictable wind-down does as much as the ingredient, in my experience. Start a few days before a known trigger rather than the morning of. Watch for how your dog actually responds over the first one to two weeks, not just the first dose. And if you’re weighing calming support against a longer-term view of your dog’s health, it’s worth reading how ingredient evidence gets evaluated across categories in our review of the best longevity supplement for senior dogs — the same “what’s proven versus what’s promising” lens applies whether you’re calming a storm-phobic dog or supporting a graying muzzle.

Where this leaves me, going forward, is cautiously optimistic rather than settled. The evidence for L-theanine is the most direct we have right now, valerian’s case rests more on tradition than trial data, and I expect that gap to narrow as more dog-specific research gets funded. Until then, I’ll keep recommending the combination approach for situational anxiety, and I’ll keep telling owners plainly which parts of that recommendation are proven and which parts are still, honestly, just promising.

These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.