The Two Studies Behind This Formula
17% testosterone increase in 8 weeks. 25.2% in 12 months. Here's what those numbers actually mean.
Two specific studies get cited across this product's marketing: an 8-week KSM-66 Ashwagandha trial and a 12-month Vitamin D3 trial. Here's what each one actually measured, separated from the marketing framing around them.
The KSM-66 Ashwagandha study
Published in the Journal of the International Society of Sports Nutrition, this double-blind, placebo-controlled trial ran men through 8 weeks of KSM-66 supplementation and recorded a 17% increase in testosterone alongside an 18% reduction in cortisol. The mechanism proposed: Ashwagandha lowers the stress hormone that directly competes with and suppresses testosterone production, so reducing cortisol indirectly supports higher testosterone.
Sleep quality, muscle strength and recovery also improved in the study population — secondary findings worth knowing about, since they're consistent with cortisol's broader role in recovery physiology.
The Vitamin D3 study
A 12-month, double-blind, placebo-controlled trial found men supplementing with Vitamin D experienced a 25.2% increase in total testosterone compared to placebo. This is described as one of the highest effect sizes ever recorded for a single supplemental nutrient in this research area — a notable finding given how common Vitamin D deficiency is, affecting an estimated 40-70% of adults in North America.
The proposed mechanism: Vitamin D3 functions more like a steroid pro-hormone than a traditional vitamin, and Vitamin D receptors exist in testes and hypothalamus tissue, positioning it to directly influence testosterone-synthesis gene expression.
What these studies don't tell you
Neither study was conducted on the finished HorsePulse product — both examined the individual ingredients in isolation, at their own studied dosages, in their own study populations. A finished six-ingredient formula combining them hasn't itself been the subject of a published clinical trial, which is standard for this supplement category but worth stating plainly rather than implying the combination itself was studied.
How this connects to timing
Both studies ran 8 weeks and 12 months respectively — not days. That's precisely why the 60-90 day supply packages exist, and why judging results after a week or two misreads what the underlying research actually measured. See the realistic timeline in our 90-day breakdown.
