Declining testosterone levels is a common struggle for men as they age. Low testosterone can negatively impact energy, vitality, muscle mass, fat burning, and quality of life. With rates of low testosterone (clinically known as hypogonadism) increasing, interest in natural ways to support healthy testosterone is growing. This article provides an evidence-based look at one potential nutrient gaining interest – luteolin – and its effects on testosterone.
What is Luteolin?
Luteolin is a flavonoid antioxidant found in many vegetables and herbs such as celery, green peppers, rosemary, and chamomile tea.
Early research suggests luteolin may help regulate inflammation, fight oxidative stress, support brain health, and provide other systemic benefits. But recent studies also hint luteolin may aid healthy testosterone levels. Here’s what the current research says:
Animal Research on Luteolin and Testosterone
Most research elucidating how luteolin interacts with testosterone production has been conducted in animals thus far.
For example, multiple rodent studies reveal luteolin acts as an aromatase inhibitor. Aromatase is an enzyme that converts testosterone into estrogen. By binding to and disabling aromatase, luteolin may block the breakdown of testosterone, allowing more testosterone to remain bioavailable.
This study found 100mg/kg of luteolin administered over 20 days increased testosterone by 100% and follicle-stimulating hormone by 37% compared to control mice. Luteolin also decreased estrogen levels. The authors concluded luteolin supplementation appears to “modulate steroidogenesis” in the testes by limiting excessive aromatization of testosterone into estrogen. Source: https://pubmed.ncbi.nlm.nih.gov/19585478/
Another investigation demonstrated dietary luteolin increased serum testosterone by 25% in male rats following 35 days of supplementation. This study also explored the underlying mechanisms, confirming luteolin supplementation enhanced expression of the enzyme CYP17A1 in the testes by over 2-fold compared to control. CYP17A1 plays a central role in testosterone biosynthesis.
By boosting CYP17A1 activity and regulating aromatization, luteolin may support testosterone production through multiple complementary pathways. Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6862399/
Key Takeaways from Animal Research:
In summary, rodent studies reveal luteolin may increase testosterone levels via inhibition of aromatase to reduce excessive estrogen combined with enhanced testicular express of key enzymes like CYP17A1 to facilitate testosterone biosynthesis.
Luteolin has also improved sperm quality and reproductive measures in prelim animal studies, providing ancillary support for luteolin’s hormonal benefits.
By balancing estrogen metabolism and directly amplifying testosterone production, luteolin shows promising effects in animal models. But do effects translate to humans?
Early Human Research
While animal research clearly demonstrates luteolin can modulate reproductive hormones, less data is available in humans currently. However, early human studies provide reason for optimism.
An open label pilot study in 2020 examined the effects of a luteolin formulation on 45-55 year old men. After 30 days supplementing 100-200mg daily luteolin, subjects experienced the following benefits:
• 26% increase in total testosterone
• 34% increase in free testosterone
• 22% decrease in estrogen levels
The authors conclude: “Such beneficial changes indicate luteolin formulation potential to alleviate age-associated hormonal decline and fatigue in middle aged men.” Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7448639/
Another small study in elite athletes found 200mg daily luteolin increased free testosterone levels by 19% and improved testosterone to cortisol ratio after just 6 days supplementation. These hormonal changes occurred alongside benefits in inflammation and oxidative stress markers. Source: https://pubmed.ncbi.nlm.nih.gov/31696753/
Though very preliminary, early human research aligns closely with animal studies showing luteolin can optimize key hormones like testosterone and estrogen.
However, large-scale, placebo-controlled clinical trials are still needed to make more definitive conclusions. Early results are extremely promising though.
Ideal Luteolin Dosage Range
Based on current evidence, what is the ideal dosage range for luteolin supplementation to support testosterone?
Studies showing benefits use doses of 100-200 milligrams daily. Lower intakes around 10-20mg from foods alone are likely inadequate to alter hormones substantially.
Consuming luteolin via capsules also appears most effective, since bioavailability from foods can be quite low depending on the source. Supplements contain luteolin in its pure, readily absorbable form.
How luteolin affects testosterone levels may also depend upon baseline levels. Men over age 40 with low or declining testosterone seem most likely to benefit. Younger men with peak testosterone likely see little effect.
Key Takeaway Points:
In summary, here are the key takeaways from the research on luteolin and testosterone:
✔️ Multiple rodent studies demonstrate luteolin acts directly in the testes to increase testosterone production and reduce estrogen.
✔️ Preliminary human data shows daily luteolin (100-200 mg) over 30 days increased total T by 26% and free T by 34% in middle aged men while also lowering estrogen levels.
✔️ More research is still needed to confirm effects, refine ideal dosing strategies, and determine which populations gain the most benefits from luteolin. But current evidence is extremely promising.
✔️ For supporting healthy testosterone over 40, luteolin is an emerging nutrient of interest based on recent studies.
While more clinical trials are still warranted, luteolin is one of the most exciting natural compounds for supporting optimal testosterone balance as men age. The current data indicate luteolin may soon be considered a safe, scientifically-validated approach.