Search for fisetin and testosterone and you will find confident claims that this flavonoid raises testosterone, improves sperm count and protects male fertility. Every one of those claims traces back to real published research. The research says something considerably more specific than the claims do.
There is a clean dividing line running through this literature, and once you see it the whole picture reorganises itself.
Key Takeaways
- In rats poisoned with arsenic, fisetin restored testosterone, LH, FSH, steroidogenic enzyme expression and sperm parameters toward normal over 56 days at 10 mg/kg.[1]
- In rats given monosodium glutamate, fisetin raised GnRH, FSH, LH and testosterone, acting on both the brain and the testis via SIRT1 and AMPK.[2]
- In mice subjected to five weeks of scrotal heat stress, oral fisetin at 10 mg/kg/day preserved testicular architecture and sperm quality.[3]
- Every result above comes from an animal that was first damaged. Fisetin rescued it back toward normal. That is not the same as raising testosterone in a healthy man.
- When researchers gave fisetin to healthy male mice and actually measured fertility, sperm quality and fertility were unchanged.[4]
- The companion study in female mice found the same: no effect on pregnancy rate, litter size or ovarian reserve.[5]
- The human studies everyone cites added fisetin to semen samples in a dish during freezing. No man swallowed anything.[6][7]
The rescue studies, and what they genuinely show
Three rodent studies form the backbone of the testosterone claim, and all three are toxicology rescue experiments.
The arsenic study is the most thorough.[1] Forty-eight male rats, four groups, 56 days. Arsenic exposure crushed antioxidant enzyme activity, raised lipid peroxidation, suppressed the steroidogenic enzymes that build testosterone (3-beta-HSD, 17-beta-HSD, StAR, CYP11A1, CYP17A1), dropped testosterone, LH and FSH, and wrecked sperm motility, count and morphology. Fisetin at 10 mg/kg substantially reversed all of it.
The monosodium glutamate study found something mechanistically interesting: fisetin acted centrally on the hypothalamic-pituitary-gonadal axis, raising GnRH along with the downstream hormones, and peripherally in the testis by raising SIRT1 and phosphorylated AMPK.[2] That is a two-site effect, not just antioxidant cleanup.
The heat stress study is the one closest to something a reader might relate to, since scrotal heat is a real-world fertility factor.[3] Mice were heated to 43 degrees Celsius for 20 minutes daily for five weeks. Oral fisetin at 10 mg/kg/day preserved testicular volume and the density of spermatogonia, spermatocytes, spermatids, Sertoli cells and Leydig cells, and lowered sperm DNA fragmentation. Importantly, the preventive group (dosed from the start of heat exposure) did better than the curative group (dosed afterward).
A 2025 study added testicular torsion, an acute surgical emergency, and found fisetin and quercetin together improved sperm parameters and a fertility index after ischemia-reperfusion injury.[8]
Taken together these show fisetin protects testicular tissue against oxidative insult. That is a coherent and well-replicated finding. It says nothing about a healthy man’s testosterone.
The two studies that tested healthy animals
This is the part that rarely appears in supplement copy.
In 2024 a group studied male mice on a choline-deficient western diet, treating them with either dasatinib plus quercetin or fisetin as senolytics from six to nine months of age, and measured sperm quality and fertility directly.[4] The result: sperm quality and fertility remained unchanged, both in the mice developing liver disease and in those receiving senolytics. The senolytics also failed to reduce liver damage or senescence, which is worth noting on its own.
The same collaboration ran the female counterpart in GeroScience.[5] Female mice were treated monthly with dasatinib plus quercetin, fisetin, or placebo from six to eleven months, then mated. Neither treatment affected pregnancy rate, litter size or ovarian reserve. Fisetin did lower lipofuscin staining and macrophage infiltration in the ovary, so it was doing something measurable at the tissue level. It just did not translate into fertility.
That dissociation is the single most useful finding in this whole topic. Fisetin moved senescence markers without moving the outcome anyone cares about. It is a clean illustration of why marker changes are not results, and it echoes what shows up in senescent cell clearance research more broadly.
The human sperm studies are test tube studies
Two recent papers used human semen, which sounds like a major step up in evidence. Read the methods.
In a 2026 study, fisetin at 15 and 30 micromolar was added to normal semen samples that were then either frozen in liquid nitrogen or exposed to hydrogen peroxide.[6] Fisetin improved motility, viability, mitochondrial membrane potential and ATP content, with 30 micromolar outperforming 15.
In a 2025 study, samples from twenty men with asthenoteratozoospermia were frozen in a cryopreservation medium supplemented with 50 micromolar fisetin.[7] Progressive motility improved, DNA fragmentation and malondialdehyde fell, chromatin condensation improved.
Both are laboratory additive studies. Fisetin was pipetted into a tube of semen outside the body. The application the authors propose, explicitly, is as an ingredient in sperm cryoprotective media for fertility clinics. Neither study involved a man taking fisetin.
The concentrations make this distinction concrete rather than pedantic. Oral fisetin absorbs poorly and clears fast, and plasma levels after a normal capsule sit far below the 15 to 50 micromolar range used in these dishes. You cannot reach a test tube concentration by swallowing a capsule.
What about the review articles?
A 2026 review in Veterinary Sciences surveys fisetin across the mammalian reproductive system, covering gonadal function and endocrine regulation.[9] It is a useful map of the field and it flags low bioavailability as a central translational challenge. Reviews like this are frequently the source cited when a product page claims fisetin supports male fertility. The review itself is more careful than the pages citing it, and it is written substantially with agricultural and veterinary applications in mind.
What to take from this
If you are considering fisetin specifically to raise testosterone, the evidence does not support that use. The hormone increases were recoveries in poisoned or heat-damaged animals, and the two experiments that gave fisetin to healthy animals and measured fertility found no effect.
If you are dealing with a real fertility problem, this is a medical issue with diagnostic pathways that identify treatable causes. A semen analysis tells you more than any supplement decision can.
The genuinely promising application here is one you cannot buy: fisetin as an additive in the freezing media that fertility clinics use to preserve sperm. That is what the human data actually supports, and it is a clinic-side decision rather than a consumer one.
If you take fisetin for other reasons, nothing here suggests it harms male reproductive function. The rodent work points the other way. Just do not expect it to move a testosterone panel, and keep the general interaction considerations in mind if you take other medications.
Frequently Asked Questions
Does fisetin increase testosterone?
Not in healthy subjects, based on current evidence. Fisetin raised testosterone in rats that had been poisoned with arsenic or monosodium glutamate, restoring hormone levels toward normal after they had been suppressed. No study has shown fisetin raising testosterone in a healthy animal or in any human, and no human trial has measured it.
Does fisetin improve sperm quality?
In damaged animal models, yes. Fisetin preserved sperm count, motility and DNA integrity in rodents exposed to arsenic, monosodium glutamate, scrotal heat stress or testicular torsion. In healthy male mice tested for fertility directly, sperm quality and fertility were unchanged. Human studies added fisetin to semen samples in the laboratory during freezing rather than giving it to men orally.
Can fisetin affect fertility if I am trying to conceive?
There is no human data either way. In mice, senolytic treatment with fisetin did not improve fertility in males or females, and did not appear to harm it. Because fisetin has documented drug interactions and no pregnancy safety data, anyone actively trying to conceive should discuss supplements with their doctor or fertility specialist.
References
- Mechanistic insight into the protective effects of fisetin against arsenic-induced reproductive toxicity in male rats. Sci Rep (2023). PMID 36813806
- Fisetin ameliorates oxidative glutamate testicular toxicity in rats via central and peripheral mechanisms involving SIRT1 activation. Redox Rep (2022). PMID 36047349
- Protective Effects of Fisetin in the Mice Induced by Long-Term Scrotal Hyperthermia. Reprod Sci (2021). PMID 34231174
- MASLD does not affect fertility and senolytics fail to prevent MASLD progression in male mice. Sci Rep (2024). PMID 39068167
- Senolytic treatment fails to improve ovarian reserve or fertility in female mice. GeroScience (2024). PMID 38358579
- Protective Effects of Fisetin Against Oxidative Stress in Human Sperm: Implications for Cryopreservation. Antioxidants (2026). PMID 42193205
- Fisetin attenuates the adverse effects of freezing and thawing procedures on the biological characteristics of human asthenoteratozoospermia samples. Reprod Biol (2025). PMID 40876296
- The synergistic activity of fisetin on quercetin improves testicular recovery in ischemia-reperfusion injury in rats. Sci Rep (2025). PMID 40199993
- Role of Fisetin in the Mammalian Reproductive System. Vet Sci (2026). PMID 42188908
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.