Serenity+: Can You Take Ashwagandha, L-Theanine and GABA Together?

For many people, the evening is when the day catches up with them. The body is tired, but the mind is still running through tomorrow's list, and sleep arrives late or stays light.

To help unwind, many add a supplement such as ashwagandha, L-theanine or GABA to their routine. But what if all three could be combined in one blend?

That was the question we had to answer when we made Serenity+. Below we look at why we made it, what's in it and what the research shows about taking them together.

Why We Made Serenity+

Stress and poor sleep are the concerns we hear about most from customers aged roughly 35 to 65. We already sold all three ingredients individually and in our Start Calm Bundle, but taking three separate supplements every evening isn't always practical. With Serenity+, we wanted an easier option: an all-in-one blend, taken as two capsules before bed. As the name suggests, it is designed to help you reach a calmer, more settled state in the evening, especially during stressful periods.

What's in Serenity+?

A two-capsule serving contains three active ingredients.

• Ashwagandha, 200 mg: the root of Withania somnifera, an Ayurvedic adaptogen, described as helping the body regulate its stress response. Our extract is standardised to 5% withanolides (10 mg), the compounds thought to drive most of its effects.
• L-theanine, 306 mg: an amino acid found mainly in tea leaves.
• GABA, 256 mg: gamma-aminobutyric acid is the brain's main inhibitory messenger, the chemical that slows nerve signalling down.
• Microcrystalline cellulose, 138 mg: a plant-derived filler.

The capsules are vegan HPMC.

How Might Ashwagandha, L-Theanine and GABA Affect the Body and Brain?

Ashwagandha. Trials have measured lower levels of cortisol, the body's main stress hormone, with ashwagandha than with placebo (1), suggesting it may work partly by damping the stress response rather than acting as a sedative.

L-theanine. In some human studies, typical doses increased alpha brain waves, linked to a relaxed but alert state, though results are inconsistent (2). Lab and animal studies suggest it also affects calming neurotransmitters such as GABA (2, 3) and crosses from the blood into the brain, which has not been measured in humans (2, 4, 5).

GABA. GABA slows nerve signalling in the brain. In rat studies, only small amounts crossed from the blood into the brain, which pumped it back out much faster than it came in; this has not been measured in humans (6–8). Researchers have suggested it may act through nerves in the gut instead, although this has not been confirmed in people (6).

What Does the Research Show?

Ashwagandha. A 2022 meta-analysis of 12 randomised controlled trials found lower stress and anxiety scores than with placebo, clearest at 300 to 600 mg a day (9). A 2024 review of nine trials found lower cortisol (1), but a 2025 analysis found no clear effect on how stressed people felt (10). For sleep, a meta-analysis of five trials found a small improvement, larger in people with insomnia, at 600 mg or more and after eight weeks or more (11).

L-theanine. In a four-week study of 30 healthy adults averaging 48 years old, 200 mg a day shortened the time taken to fall asleep and reduced sleep disturbances compared with placebo, although the effects were modest (12).

GABA. A 2020 systematic review found limited evidence for stress and very limited evidence for sleep (13). In a small trial of 40 people with insomnia symptoms, 300 mg a day for four weeks cut the time to fall asleep in a sleep laboratory from about 13 minutes to 6, but only 10 took the placebo, so the comparison is weak (14).

The combination. In animal studies, GABA and L-theanine together improved sleep more than either alone (15). A 2026 placebo-controlled trial in 128 menopausal women tested a supplement combining both alongside magnesium and SAMe. Sleep scores improved and self-reported sleep rose by about 40 minutes a night, but the results can't be attributed to GABA and L-theanine alone, and the trial was run largely by the manufacturer (16). No trial has yet tested all three Serenity+ ingredients together.

Serenity+ contains more L-theanine (306 mg) and slightly less GABA (256 mg) than the 200 mg and 300 mg tested, while its 200 mg of ashwagandha is below the 300 to 600 mg used in most trials. We chose a conservative ashwagandha dose because of the safety concerns raised by Germany's Federal Institute for Risk Assessment (BfR), which we cover below.

How to Take Serenity+

Take two capsules with water 30 to 60 minutes before bed, alongside a regular bedtime and a dark, cool bedroom. L-theanine has not been found to cause drowsiness at these doses (2). Most trials above ran for four to eight weeks of daily use (11, 12, 14), so give it several weeks before judging the effect.

Read more about sleep and stress in our other articles: How Can We Cope with the Stress of Daily Life? and 50 and Not Sleeping Well, What Do I Do?.

Is Serenity+ Safe?

Side effects in ashwagandha trials were mostly mild to moderate (1, 11). Rarely, ashwagandha has been linked to liver injury; in one case series, liver tests returned to normal within one to five months of stopping in four of the five cases (17). L-theanine and GABA were well tolerated in the trials above, with occasional stomach discomfort or headache reported for GABA (12, 14).

The BfR advises against food supplements containing ashwagandha, especially for children, pregnant and breastfeeding women and people with liver disease, so Serenity+ is not suitable for these groups. It also flags possible effects on blood sugar and hormone levels. If you have a thyroid condition or take regular medication, including for blood sugar, blood pressure, sleep or the immune system, check with your doctor or pharmacist first.

The Takeaway

So can you take ashwagandha, L-theanine and GABA together? No trial has tested all three at once, but the research on the individual ingredients is strongest for ashwagandha and L-theanine, and GABA and L-theanine have early evidence as a pair. For most adults, the main thing to check is whether ashwagandha suits you. We combined them because they appear to act in different ways, ashwagandha on the body's stress hormones and L-theanine and GABA on calming signals in the brain. Serenity+ is best suited to adults who want a simple evening routine for stressful periods, without taking three separate supplements.

Serenity+ is available in our shop. If you would rather adjust each dose yourself, the three ingredients are also sold separately in the Start Calm Bundle.

Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle. This article is not medical advice.

Literature Sources

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