That's a reasonable question. The patented KSM-66 extract is, according to the manufacturer's specification, standardized to at least 5% withanolides, yet this product's ingredients list states only the total amount of 'ashwagandha active substance' (500 mg), without a separate indication of withanolide content. This means the exact standardization cannot be verified from the product information, even though it is named KSM-66. For comparison, some other products in this category (e.g. with KSM-66 extract at 200 mg) also list the mg of withanolides separately on the label, allowing for better comparison with the doses used in clinical research (Pakhale et al., 2025).

500 mg of extract per day falls within the range used in numerous clinical studies on the effect of ashwagandha on stress and cortisol - these mostly used between 250 and 600 mg/day of standardized extract over 30-112 days (Della Porta et al., 2023), while a pilot study with KSM-66 used 600 mg/day (Pakhale et al., 2025). The dose in this product is therefore solidly within this range, which increases the likelihood that it will align with the doses at which studies detected effects on cortisol. This does not guarantee an individual result - responses vary between people - but the dose itself is not a limiting factor.

Some users report similar feelings at higher doses of ashwagandha - reduced motivation or mild emotional numbness - although these are individual, subjective experiences and not a systematically documented, common side effect in clinical studies, where the side effects of KSM-66 were otherwise comparable to placebo (Winther, 2026). If you notice such an effect, it makes sense to temporarily stop taking it and, if needed, lower the dose or consult a doctor, especially if you are also taking other medications that affect mood.

This product's label does not include a specific warning regarding the thyroid, but that does not mean there is no risk. The literature describes rare cases of thyrotoxicosis with ashwagandha use, while in hypothyroidism some sources even report normalization of thyroid hormones - so the effect depends on the baseline condition (NIH ODS, 2025; Winther, 2026). Since this is an individual, medically relevant condition, we recommend that you consult a doctor or endocrinologist familiar with your medical history before using this or any ashwagandha product.