Sexual function
Erectile function
Also searched as Erectile function.
You want it healthy: sexual function reflects sound vascular, hormonal and psychological balance.
In depth
Desire, arousal and function — three separable things that the literature routinely conflates. They are kept apart because an intervention can move one and leave the others untouched.
What drives it
Testosterone increases it.
Corona 2014 meta-analysis, J Sex Med — testosterone supplementation improves erectile function and male sexual response in hypogonadal men. PMID 24697970. Testosterone regulates brain regions involved in sexual motivation including the hypothalamus; lower testosterone is associated with decreased libido, reduced sexual activity and satisfaction (Cureus systematic review). Again DHT-independent: maintenance of libido and sexual behavior does not require conversion of testosterone to DHT, and men with 5-alpha-reductase deficiency develop normal libido at puberty. only 1-5 percent of circulating testosterone is free and physiologically active — 95-98 percent is bound to SHBG and albumin, so total testosterone is the wrong measure. Normal range in healthy men is stated as 264-916 ng/dL, a nearly four-fold spread. PMID 24697970
Blood flow (nitric oxide) increases it.
Erection is a nitric-oxide event, and the proof is a drug class built on it: NO released in the corpus cavernosum activates guanylate cyclase, raising cGMP and relaxing the smooth muscle so blood can enter. PDE5 inhibitors do nothing but prevent the breakdown of that cGMP — sildenafil has no direct relaxant effect of its own — and they have been first-line therapy for erectile dysfunction since their introduction (PMC6003652, PMC4563010). Testosterone matters, but it acts largely by stimulating NO synthase; the endothelium is where the mechanism lands. The NO-cGMP axis characterization earned the 1998 NOBEL PRIZE in physiology OR medicine and is the mechanistic basis of every PDE5 inhibitor. Pharmacology confirms the direction: PDE5 inactivates cGMP and terminates the relaxation; inhibiting PDE5 preserves cGMP and enhances erection. Human trial, and it runs both ways: 21 men with ED given sildenafil on demand for 12 weeks improved IIEF-EF from 17.9 to 26 (P<0.05) and showed higher eNOS protein afterwards, alongside falls in hs-CRP and sICAM-1 (Int J Impot Res doi 10.1038/ijir.2009.51). endothelial NO is prerequisite but not alone — neuronal NOS contributes in parallel, and age-related ED also involves lost cavernosal smooth-muscle content and impaired veno-occlusion, which more NO cannot fix. doi 10.1038/ijir.2009.51 · PMC6003652
Hormone-binding protein reduces it.
SHBG does not change how much testosterone you make — it changes how much of it can ACT, which is why this pathway runs to function and not to Total Testosterone. In men roughly 70% of circulating testosterone is bound with high affinity to SHBG, 20-30% to albumin, and only about 1-2% circulates free; SHBG is the principal determinant of the split between bound and free, and the free-hormone hypothesis holds that only the unbound fraction can cross the membrane and act (PMC8318754, Endocrine Reviews PMC6287254). So a high SHBG can produce a functional deficiency on a perfectly normal total-testosterone result — which is exactly why expert panels recommend measuring free testosterone whenever SHBG is disturbed by obesity, diabetes, aging, thyroid or liver disease. PMC8318754
Oxidative stress reduces it.
Three separate attacks on one molecule, numbered in the source: (1) superoxide inactivates NO to form PEROXYNITRITE, and PEROXYNITRITE attacks and destroys TETRAHYDROBIOPTERIN, a critical cofactor in NO synthesis. (2) advanced glycation end products promote superoxide formation as well as directly inactivate NO. (3) arginase II degrades L-arginine, a substrate required for NO synthesis. Destroy the product, destroy the cofactor, remove the substrate. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Mitochondrial energy increases it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Reduces sugar damage reduces it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Type 2 diabetes reduces it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Insulin sensitivity increases it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Calms body-wide inflammation reduces it.
the molecular mechanisms underlying endothelial dysfunction, including reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Calms inflammation reduces it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Cell turnover reduces it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Cell migration switch reduces it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Blood pressure reduces it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
Lowers cholesterol increases it.
Named across six reviews of endothelial dysfunction as part of the shared mechanism set: reduced nitric oxide availability, oxidative stress, inflammatory responses, apoptosis of endothelial cells, and the emerging concept of endothelial-mesenchymal transition. doi 10.3390/jcm15041621 · PMID 33923709 · PMC11988752
What it drives
It increases Mood.
10.1016/j.jsxm.2021.11.011 — This is what the symptom costs rather than what it causes physiologically. It is shown at reduced weight because no separate effect size has been reported for this arm. The asymmetry is deliberate and stated. Sexual function and mood co-travel; the Mood (Positive Affect) → Female Desire & Arousal link is already drawn on the depression literature, so this is the return arm on weaker evidence. This link rests on the reviews of this outcome as a whole, and no effect size specific to it has been reported. doi 10.1016/j.jsxm.2021.11.011
It reduces Calm under stress.
10.1016/j.jsxm.2021.11.011 — This is what the symptom costs rather than what it causes physiologically. It is shown at reduced weight because no separate effect size has been reported for this arm. The asymmetry is deliberate and stated. Performance anxiety is a named contributor and a consequence. Bidirectional and drawn one way. doi 10.1016/j.jsxm.2021.11.011
It increases Women's hormone balance.
The genitalia and lower urinary tract share common estrogen receptor function. The receptor change is the estrogen receptors alpha and beta ARE present in the vagina, vestibule, urethra and bladder TRIGONE - while both receptors can be found in premenopausal women, only estrogen-beta receptors can be detected in postmenopausal women. The tissue does not merely see less hormone; it loses a receptor subtype. And a pH loop with a clinical endpoint: estrogen maintains vaginal glycogen, lactobacilli convert it to lactic acid holding pH at 3.5-5.0; loss of estrogen is responsible for the reduction of Lactobacillus, changing the vaginal fluid to an alkaline pH of 5.0 OR above, which promotes overgrowth of gram-negative rod fecal flora, inducing vaginal infection and UTI. Scale and underdiagnosis: GSM affects 40-54 percent of postmenopausal women and 15 percent of premenopausal women, and around 60 percent of these women have never had a diagnosis of GSM before. doi 10.3389/frph.2021.779398 · PMC10692865
It increases Urinary health.
The genitalia and lower urinary tract share common estrogen receptor function. The receptor change is the estrogen receptors alpha and beta ARE present in the vagina, vestibule, urethra and bladder TRIGONE - while both receptors can be found in premenopausal women, only estrogen-beta receptors can be detected in postmenopausal women. The tissue does not merely see less hormone; it loses a receptor subtype. And a pH loop with a clinical endpoint: estrogen maintains vaginal glycogen, lactobacilli convert it to lactic acid holding pH at 3.5-5.0; loss of estrogen is responsible for the reduction of Lactobacillus, changing the vaginal fluid to an alkaline pH of 5.0 OR above, which promotes overgrowth of gram-negative rod fecal flora, inducing vaginal infection and UTI. Scale and underdiagnosis: GSM affects 40-54 percent of postmenopausal women and 15 percent of premenopausal women, and around 60 percent of these women have never had a diagnosis of GSM before. doi 10.3389/frph.2021.779398 · PMC10692865
It increases Orgasm.
Crocin, at all doses, and the extract, especially at the higher doses, increased MF, if and EF behaviors and reduced EL, IL and ML parameters. Safranal did not show aphrodisiac effects. PMC4045980
Blends that modulate it
Each blend page names this pathway and carries the study behind its claim.
See it on the map
Open the causal map to follow this pathway upstream and downstream, arrow by arrow, each with its study.