Ashwagandha, or Withania somnifera, is a revered herb in traditional Ayurvedic practice and is widely recognized as an adaptogen that helps the body manage stress and maintain balance. Many users find that it consistently makes them feel calm or noticeably drowsy. This common experience is not a conventional side effect, but a direct result of the herb’s powerful biological activity. The plant’s scientific name, somnifera, translates from Latin as “sleep-inducing,” offering a clear clue about its inherent properties. This relaxing effect is precisely why the supplement is often sought to support anxiety relief and improved sleep quality.
The Primary Mechanism Behind Sedation
The tranquilizing effect of this herb is rooted in its interaction with the central nervous system, primarily through two distinct biological pathways. The active compounds in the plant, naturally occurring steroids called withanolides, are responsible for these calming actions. These compounds mimic or enhance the activity of gamma-aminobutyric acid (GABA), which is the chief inhibitory neurotransmitter in the brain.
By acting on the GABAergic system, ashwagandha effectively reduces neuronal excitability and slows down communication between nerve cells. This enhancement of inhibitory signaling leads directly to feelings of relaxation, reduced anxiety, and a state conducive to sleep. The root extract has been shown to increase both the expression and activity of GABA receptors in the brain.
The herb also modulates the Hypothalamic-Pituitary-Adrenal (HPA) axis, the body’s central stress response system. Ashwagandha reduces the activation of this axis, leading to a significant decrease in the stress hormone cortisol, especially in individuals with chronically elevated levels. Lowering cortisol facilitates a shift from a “fight-or-flight” state to a more restful one, which promotes calm and can induce sleepiness.
The combination of GABAergic action and HPA axis modulation creates a powerful, two-pronged approach to promoting relaxation. Decreasing the body’s overall stress load while simultaneously calming the nervous system explains why the herb is effective at reducing the mental and physical tension that often precedes drowsiness.
Managing Timing and Dosage for Optimal Results
The best time to take ashwagandha depends on the user’s specific health goals. If the primary objective is to leverage the sedative effect for better rest, taking the full dose in the evening, about 30 minutes to an hour before bed, is recommended. This timing allows the calming effects to peak as the body prepares for sleep.
For individuals seeking stress-management benefits without daytime drowsiness, adjusting the timing and dosage is necessary. Splitting the total daily dose, such as taking a smaller portion in the morning and the remainder in the late afternoon, can mitigate acute sleepiness. This strategy provides a consistent level of active compounds throughout the day to support stress resilience without a large, single influx that might trigger noticeable drowsiness.
The standard daily dosage in studies often ranges from 300 to 600 milligrams of a standardized root extract. Start at the lower end of this range and gradually increase the amount while observing the body’s response. Consistency is important, as the herb’s full adaptogenic effects on the HPA axis can take several weeks to fully manifest. Experimenting with different formulations can also influence the perceived effect, so paying close attention to the product label is wise.
When Sleepiness Signals a Problem
While mild drowsiness is a common and expected outcome, excessive or debilitating sleepiness can signal a potential safety issue or an interaction. Because ashwagandha has a GABA-enhancing effect, combining it with other sedative medications can be dangerous. This includes prescription sleep aids, anti-anxiety medications like benzodiazepines, and some over-the-counter antihistamines.
The combined effect of the herb and these medications can intensify drowsiness to an unsafe degree, potentially causing respiratory depression or excessive central nervous system depression. Individuals should exercise caution and avoid driving or operating heavy machinery until they understand exactly how the herb affects them. If the feeling of sleepiness is overwhelming or prevents normal daily function, it is a clear sign that the dosage is too high or that a problematic interaction is occurring.
Other medications that can interact include those for blood pressure, diabetes, and thyroid conditions, so consulting with a healthcare provider before starting the supplement is important. Severe drowsiness could also be a sign of an underlying health issue or simply an indication that the herb is not suitable for a person’s individual chemistry. Stopping the supplement and seeking medical advice is the safest course of action if adverse effects like severe sedation are experienced.