Written by Keely Puchalski, ND. Results from this 8-week prospective, randomized, double-blind, placebo-controlled, parallel-group trial suggest that 300 mg twice daily of standardized ashwagandha root extract (KSM-66) improved self-reported sexual desire, erectile function, and semen parameters in men with mild-to-moderate sexual dysfunction compared to placebo, though methodological inconsistencies and data quality concerns limit confidence in the magnitude and generalizability of the findings.

Ashwagandha (Withania somnifera) is classified in Ayurvedic medicine as a Rasayana — a restorative herb supporting vigor, vitality, and reproductive capacity. Its active constituents, steroidal lactones known as withanolides, suppress hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, reduce cortisol, and exert antioxidant effects in seminal plasma.^1,2 Chronic stress is a well-established driver of male sexual dysfunction through cortisol-mediated suppression of testosterone and libido.³ A 2018 systematic review confirmed semen parameter improvements in oligospermic men but identified only one qualifying RCT among four clinical trials.^4–6 Available evidence in men with mild sexual dysfunction was even more limited. This trial evaluated a standardized ashwagandha root extract (KSM-66) on sexual health outcomes in adult men over 8 weeks.

Seventy-six men aged 30–50 with mild-to-moderate erectile dysfunction (IIEF score 11–16) presenting at a single clinical site in India were randomized 1:1 to KSM-66 Ashwagandha® (Ixoreal Biomed) 300 mg or matched starch placebo twice daily for 8 weeks. KSM-66 is a root-only aqueous extract standardized to >5% withanolides. Inclusion required a stable heterosexual partnership and willingness to attempt intercourse at least four times per two-week period; organic, endocrine, or psychiatric causes of dysfunction were exclusionary. Primary outcomes were the Sexual Desire Inventory-2 (SDI-2; a 14-item validated self-report of dyadic and solitary sexual desire, with higher scores indicating greater desire) and Satisfying Sexual Events (SSEs; a participant diary of intercourse frequency, duration, penetration success, orgasm count, and non-intercourse interactions). Secondary outcomes included the International Index of Erectile Function (IIEF; a 15-item validated questionnaire covering erectile function, orgasm, desire, and satisfaction),⁸ SF-12 quality of life, WHO-standardized semen parameters, and serum testosterone. Statistical analysis used two-sample t-tests and repeated-measures ANOVA; no correction was applied for multiple comparisons across secondary endpoints.

Key Findings:

1. SDI-2 (primary): Significant between-group difference at Week 8 (p<0.001; Cohen’s d = 1.41). Ashwagandha group improved 62% from baseline; placebo group declined 21%.
2. SSEs (primary): All six subdomains significantly favored ashwagandha at Week 8 (p = 0.011 to <0.001), with within-group improvements of 29–55% vs. modest 2–8% changes in placebo. Non-intercourse interactions (p=0.104) and orgasm count (p=0.150) were non-significant at Week 4.
3. IIEF (secondary): Significant between-group improvement at Week 8 (p<0.001; mean difference 15.11; d = 1.81).
4. SF-12 (secondary): Both mental (MCS) and physical (PCS) component scores significantly favored ashwagandha at Week 8 (both p<0.001); between-group effect sizes at Week 8 were d = 2.80 (MCS) and d = 3.40 (PCS).
5. Semen Parameters (secondary): Significant improvements in semen volume (+36%; p<0.001), total sperm count (+38%; p=0.015), sperm concentration (+33%; p=0.013), and total sperm motility (+87%; p=0.002) at Week 8.
6. Testosterone (secondary): Numerical increases in both total and free testosterone did not reach statistical significance (total T: p=0.223; free T: p=0.099).
7. Adverse Events: No adverse events or serious adverse events were reported in either group.

On the whole, this trial supports the use of KSM-66 in mild-to-moderate sexual dysfunction and has meaningful structural strengths: a double-blind, placebo-controlled design with pre-specified ITT analysis, multiple validated outcome instruments, WHO-standardized semen analysis by a single blinded technician, a well-characterized and clinically studied extract (KSM-66) with defined withanolide content, and high treatment compliance. The absence of serious adverse events and steady hepatic and renal biomarkers over 8 weeks are also clinically relevant findings.

That said, several methodological inconsistencies and data quality concerns require naming. There are inconsistencies in baseline data, and the Methods section is not very clear. For example, Table 5 reports a standard deviation of exactly 0.00 for the change-from-baseline in bilirubin, BUN, ALT, AST, and ALP in the ashwagandha group — each showing an identical mean change of −0.10 across 34 subjects. A zero SD on biologically variable lab markers in 34 people is physiologically impossible; the p<0.001 values for these parameters are likely artifacts of a near-zero denominator. The honest read is likely that ashwagandha did not adversely affect hepatic or renal function — a useful safety signal — but claims of significant reductions in liver enzymes are unsupported. Tables 1 and 4 also show discordant baseline semen values, and Table 1 lists an SD exceeding the mean for sperm concentration — mathematically impossible for a non-negative variable. The secondary semen and hormonal endpoints are further undermined by extreme baseline variability (testosterone SD of 337 ng/dL on a mean of 697; sperm count SD exceeding 70% of the mean), making group averages difficult to interpret, and an unverified abstinence window (≥2 days) with no confirmation of consistency between subjects or timepoints — a known confounder for semen volume and concentration. Beyond data quality, baseline sexual activity relied on two-week retrospective recall while follow-up used prospective daily diaries — an asymmetry likely explaining the unusual 21% placebo SDI-2 decline and undermining change-from-baseline comparisons in primary outcomes. The 8-week duration falls short of a complete spermatogenic cycle (~74 days), and zero dropout across 76 participants despite logistically demanding criteria is unexplained and arguably implausible. The Discussion also frames non-significant testosterone findings as providing “biological foundation” for the sexual benefits observed — contradicting the study’s own significance threshold.

In isolation, this paper warrants cautious interpretation. Within the broader ashwagandha literature — including prior RCTs showing consistent directional effects on semen quality, testosterone, and sexual function⁷ — it adds a meaningful, if methodologically imperfect, data point. Future trials should employ prospective measurement throughout, a minimum 12-week duration for semen endpoints, standardized abstinence protocols, stratified enrollment or individual-level data reporting to distinguish men with borderline hormonal or semen parameters from healthy controls, blinding verification, and pre-specified multiplicity correction.

Source: Khanna A, Khanna M, Panchal P. Efficacy and safety of ashwagandha root extract on sexual health in healthy men: a prospective, randomized, double-blind, placebo-controlled study. Front Reprod Health. 2026;8:1774098. doi:10.3389/frph.2026.1774098

Click here to read the full text study.

Posted July 1, 2026.

Keely Puchalski, ND, is a licensed naturopathic physician and natural products expert with a clinical focus on mental health. She earned her ND from Sonoran University of Health Sciences (formerly Southwest College of Naturopathic Medicine) in 2020. Dr. Puchalski has conducted original research in botanical medicine, with discoveries leading to multiple patents and high-impact journal publications. She has authored peer-reviewed papers and presented her work at national conferences, webinars, and educational events.

She is the co-founder of Restored Counseling & Wellness Center in Gilbert, AZ, where she leads a collaborative team of therapists and naturopathic doctors dedicated to integrative mental health care:  https://restoredcw.com.

References:

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