Ashwagandha
Withania somnifera

Ashwagandha (Withania somnifera) is a plant from Ayurvedic medicine that has been used for more than two thousand years to manage stress and improve rest. In the shop you will find it as a supplement, usually in capsules (the powder tastes very bad).

It is worth knowing this from the outset: ashwagandha is neither a sedative nor an antidepressant, it does not act within hours, and it has no effect from a single one-off dose. Clinically measurable changes appear between the fourth and eighth week of continuous use, and quality studies cover treatments of up to three months.

The solid evidence for ashwagandha is concentrated in three areas: it serves to reduce perceived stress and cortisol levels, it improves sleep quality, and it provides modest support for recovery after exercise. For cognition, longevity and athletic performance there are promising but still preliminary data.

Ashwagandha is intended for adults living with chronic stress, sleep problems or mild anxiety, who are looking for natural support backed by reasonable evidence.

It also has two secondary profiles with more preliminary but significant evidence: physically active people seeking support for recovery after exercise, and adults who notice mild cognitive complaints — occasional forgetfulness, difficulty concentrating — without any medical diagnosis involved.

Unlike other supplements where the dose is universal, with ashwagandha the dose depends on the commercial extract you are taking. The three brands with scientific backing (KSM-66, Sensoril and Shoden) use different concentrations of the active compounds, so the effective doses are also different. The practical rule is to follow the recommended dose of the brand on your bottle; if your product does not name any identifiable brand, it is wise to be wary of its quality.

Clinically measurable effects appear from the fourth week of continuous use and their peak usually occurs in the eighth week. Quality studies cover treatments of six to twelve weeks. Beyond three months, the available evidence becomes scarce.

Ashwagandha is absorbed better when you take it with food containing fat. The active compounds — the withanolides — are fatty molecules, they do not dissolve in water. That is why the Ayurvedic tradition combined it with warm milk and clarified butter, a preparation called golden milk. In modern practice no such ceremony is needed: it is enough to take it with the main meal of the day, or with a whole-milk yogurt, a handful of nuts or a glass of milk.

There are two supplements that combine well with ashwagandha in the context of sleep and anxiety: magnesium glycinate (which also acts on the GABAergic system) and L-theanine (an amino acid from green tea with a calming daytime effect), although the combination is not validated by formal clinical trials.

Unlike other supplements where a gram is a gram, with ashwagandha the extract matters more than the amount. Two bottles that say “ashwagandha 500 mg” can contain radically different concentrations of active compounds depending on how the plant has been processed. That is why the industry developed standardized extracts — preparations with a guaranteed percentage of withanolides, validated in clinical trials. There are three with real scientific backing.

Ashwagandha has a notably solid base of clinical evidence for a medicinal herb. More than thirty clinical trials in humans have evaluated its effects, many of them randomized, double-blind and placebo-controlled. The consensus concentrates on three conclusions: the effect on perceived stress and cortisol is consistent and reproducible, the effect on sleep quality is clear but more modest, and the effects on physical performance and cognition are promising but limited by the composition of the samples.

A warning worth having from the start: the vast majority of pivotal trials are funded by the manufacturers of the commercial extracts. This does not invalidate the results, but it conditions how the body of evidence should be read. The development of this cross-cutting warning is in the extracts and brands section.

Ashwagandha is generally well tolerated in healthy adults, but it is not for everyone. There is a group of clinical situations in which it should not be taken, and another group in which it requires prior medical consultation. If you fit any of these profiles, this section is the most important in the whole page.

Consult your doctor before starting if you take any chronic medication (antihypertensives, antidiabetics, anxiolytics, antidepressants, thyroid hormone, anticoagulants), you have an autoimmune disease, you are being treated for a hormone-sensitive cancer, you are going to undergo surgery in the next two weeks, or you are seeking pregnancy in the short term.