adaptogen

Ashwagandha

Ashwagandha (Withania somnifera) is one of the most important herbs in Ayurvedic medicine, used for over 3,000 years as a rejuvenating tonic. Classified as an adaptogen, it helps your body manage and adapt to stress by modulating the hypothalamic-pituitary-adrenal (HPA) axis and reducing cortisol levels. Modern clinical trials have validated many of its traditional uses, particularly for stress reduction, anxiety relief, and improved sleep quality.

Beyond stress management, ashwagandha has demonstrated impressive benefits for physical performance and body composition. Research shows it can increase VO2 max, improve cardiorespiratory endurance, and support testosterone levels in men. A 2015 study found that ashwagandha supplementation combined with resistance training led to significantly greater gains in muscle strength and size compared to placebo.

To optimize the benefits of ashwagandha, look for standardized root extracts such as KSM-66 or Sensoril, which have the most clinical evidence behind them. KSM-66 is a full-spectrum extract standardized to 5% withanolides, while Sensoril is a leaf and root extract standardized to 10% withanolides. Both are effective, though they may differ slightly in their effects.

Key Benefits

Significantly reduces cortisol levels and perceived stress
Reduces anxiety symptoms comparable to some anxiolytic medications
Improves sleep quality and sleep onset latency
Supports physical performance and cardiorespiratory endurance
May support healthy testosterone levels in men
Has anti-inflammatory and antioxidant properties

Potential Risks

May increase thyroid hormone levels, affecting thyroid medication needs
Can cause drowsiness, especially at higher doses
Not recommended during pregnancy
Rare reports of liver injury at very high doses or with contaminated products

Dosage Guide

300–600mg/day

Refers to standardized root extract (KSM-66 or Sensoril). Raw powder requires higher doses (3-6g). Effects typically noticed after 2-4 weeks of consistent use. Some practitioners recommend cycling (8 weeks on, 2 weeks off).

Warnings

  • If on thyroid medication, consult your doctor before using
  • May enhance the effects of sedatives and anxiolytics
  • Not recommended during pregnancy or breastfeeding
Calculate your personalized dose →

When to Take

Best Time

Morning for energy and stress resilience, or evening for sleep support

With Food?

Yes, take with a meal

Spacing

Take with a meal to improve absorption and reduce potential stomach upset

Available Forms

Capsule (KSM-66)

good

Most studied extract. Full-spectrum root extract standardized to 5% withanolides.

Powder

moderate

Traditional preparation. Has a strong earthy taste. Requires higher doses.

Liquid Extract

good

Fast absorption. Convenient for dose adjustment.

What to Pair With Ashwagandha

Use Caution With

Thyroid Medication

May increase thyroid hormone levels and alter medication needs

SSRI Antidepressants

Combined sedative effects may cause excessive drowsiness

Check your full stack for interactions →

Research on Ashwagandha

Efficacy of Ashwagandha in reducing stress and anxiety: systematic review

PubMed ID: 34254920

Ashwagandha improves cardiorespiratory endurance in athletes

PubMed ID: 33034015

Thyrotoxicosis following Ashwagandha ingestion: case reports

PubMed ID: 32219282

Frequently Asked Questions About Ashwagandha

What is the difference between KSM-66 and Sensoril ashwagandha?

KSM-66 is a full-spectrum root-only extract standardized to 5% withanolides, while Sensoril uses both root and leaf and is standardized to a higher 10% withanolides. KSM-66 tends to be more energizing and is popular for daytime use, physical performance, and testosterone support. Sensoril is often considered more calming and is frequently chosen for anxiety and sleep. Both have strong clinical evidence behind them.

Should I cycle ashwagandha?

While there is no definitive requirement to cycle ashwagandha, many practitioners recommend taking breaks to prevent tolerance and allow your HPA axis to maintain its own regulatory function. A common approach is 8 weeks on followed by 2 weeks off, or 5 days on and 2 days off each week. Some people take it continuously without issues, but cycling is generally considered a prudent approach for long-term use.

Can ashwagandha affect my thyroid?

Yes, ashwagandha has been shown to increase thyroid hormone levels (T3 and T4) in several studies. This can be beneficial for people with subclinical hypothyroidism, but it may be problematic for those already on thyroid medication or those with hyperthyroidism. If you have any thyroid condition or are taking thyroid medication, consult your endocrinologist before starting ashwagandha supplementation.

Calculate Your Ashwagandha Dose

Want to optimize your health?

Create your free account and start tracking what matters.

Sign Up Free