The key ingredients are listed below:

Muira Puama Extract
A powerful Amazonian aphrodisiac known as “potency wood.” It works by increasing sensitivity in the nerve endings of the genital region and stimulating sexual desire. In a published clinical study by sexologist Dr. Jacques Waynberg involving 262 men with low sexual desire or inability to attain or maintain an erection, 62% rated the treatment as having a dynamic effect on libido after two weeks, and 52% of those with erectile dysfunction rated it as beneficial. Research suggests Muira Puama influences the brain’s limbic system — which controls emotional responses including sexual desire and arousal — and appears to enhance nitric oxide production, crucial for vasodilation and increased blood flow.

Maca Extract
An ancient Peruvian root that acts directly on male hormonal balance. It increases physical energy levels, improves sexual stamina, and elevates natural sperm production. Maca has been studied for its non-hormonal mechanism of action — supporting libido and energy through physiological pathways related to mood and energy metabolism rather than directly raising testosterone, making it a safe and well-tolerated daily vitality ingredient.

Catuaba Bark
Extracted from the bark of a Brazilian tree, this ingredient functions as a natural stimulant for the central nervous system. It improves blood circulation to the penis, enhances arousal, and reduces sexual fatigue. Native Amazonian traditions have long combined Catuaba with Muira Puama specifically for improving libido and addressing erectile difficulties — a pairing also reflected in Horse Boost’s formula.

Ashwagandha
The formula’s most extensively researched ingredient for male sexual health in 2025–2026. An Indian adaptogen that reduces cortisol levels and increases free testosterone in the body. The most recent clinical evidence is extraordinarily compelling: a prospective, randomized, double-blind, placebo-controlled clinical trial published in Frontiers in Reproductive Health (February 2026) showed statistically significant gains in erectile function (IIEF), sexual desire (SDI-2), sexual activity frequency, orgasmic function, and partner-related sexual outcomes in healthy men. A separate 8-week randomized, double-blind, placebo-controlled study published in 2025 found a 112.84% increase in the level of sexual desire scores and 108.12% increase in the number of satisfying sexual event scores. Additionally, Ashwagandha improves semen parameters: significant improvements were observed for semen volume, sperm number, sperm concentration, and sperm morphology. No adverse events were reported in these studies.

Arginine
An amino acid that the body converts into nitric oxide — the same compound that erectile dysfunction medications stimulate. It dilates blood vessels in the penis, allowing more blood to flow there, resulting in harder, fuller, and more responsive erections. Arginine is the direct precursor to endothelial nitric oxide synthase (eNOS) and the main precursor of nitric oxide released from vascular endothelium — a foundational mechanism in cardiovascular and sexual health research.

Tribulus Terrestris
A plant used for centuries to increase male virility. It stimulates the production of luteinizing hormone, which signals the body to manufacture more testosterone. A systematic review of clinical trials found that despite inconclusive evidence for Tribulus as a standalone testosterone booster, it presented advantageous effects for patients with erectile dysfunction in the majority of relevant studies reviewed — contributing meaningfully to the formula’s overall hormonal support synergy.