Ashwagandha

Ashwagandha is the root of Withania somnifera, used for centuries in Ayurvedic medicine and marketed today mainly as a stress and testosterone supplement. It is classified as an adaptogen, a term describing substances claimed to help the body resist stress broadly, though adaptogen is a marketing and traditional-medicine category, not a recognized pharmacological mechanism class.

A randomized, double-blind, placebo-controlled study gave chronically stressed adults a standardized high-concentration ashwagandha root extract and measured serum cortisol along with stress-scale scores, finding significant reductions in both, compared to placebo, over roughly two months [1]. A separate 16-week, randomized, double-blind, crossover study in overweight men aged 40-70 with mild fatigue gave a different standardized extract (Shoden, delivering 21 mg of withanolide glycosides) and found an 18% greater increase in DHEA-S (P=0.005) and a 14.7% greater increase in testosterone (P=0.010) compared to placebo [2]. Neither hormone shift is enormous, but both were statistically significant against a placebo arm in a crossover design, which controls for individual variation better than a simple parallel trial.

What the evidence does not show: in that same 16-week crossover trial, there was no significant between-group difference in salivary cortisol or estradiol, and no significant difference in self-reported fatigue, vigor, or sexual and psychological well-being between ashwagandha and placebo, despite both groups reporting improvement over time [2]. That is a direct contradiction of the stress-relief and vitality claims usually attached to ashwagandha marketing, sitting inside the same trial that found the testosterone effect. A 2025 systematic review and meta-analysis examining the herb's dual claims concluded that ashwagandha produced a significant reduction in measured cortisol across pooled trials but no significant effect on perceived stress, the subjective outcome that matters most to a person deciding whether to take it. This pattern, real changes in a blood biomarker without a matching change in how a person actually feels, recurs across multiple ashwagandha trials and is the central gap in the evidence base.

No confirmed Blueprint product page lists ashwagandha as a standing daily ingredient with a specific verified dose as of this review, so no self-experimentation data point from that program is attributed here.

Critics of ashwagandha research point to inconsistent extract standardization across studies (root-only vs. root-and-leaf, different withanolide concentrations under different trade names) as a major reason results do not replicate cleanly from one product to another, and note that most positive-outcome trials are funded by the ingredient manufacturer whose specific extract was tested. A separate safety concern has grown since 2017: the NIH LiverTox database documents a recurring pattern of clinically apparent liver injury linked to commercial ashwagandha products, typically presenting as jaundice 2 to 12 weeks after starting the supplement with a cholestatic or mixed injury pattern; most cases resolve after stopping the product, but rare fatal cases and at least one liver transplant have been reported, mainly in people with pre-existing liver disease [3]. This pattern was not seen in controlled clinical trials, which raises the possibility that contamination, individual susceptibility, or dose differs between trial-grade extract and commercial products.

The honest takeaway: ashwagandha lowers cortisol and modestly raises testosterone and DHEA-S in some trials, but multiple studies measuring how people actually feel, less stressed, more energetic, find no significant benefit over placebo in the same populations, and rare but serious liver injury reports mean it is not risk-free.

Products with this: Ashwagandha