Horny Goat Weed for ED
Epimedium / icariin
Evidence grade 2 of 5, Thin. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- N/A (supplement)
Reference only. Not medical advice.
What can go wrong
Generally tolerated at typical doses; possible dizziness, tachycardia, and dry mouth. Because it shares the PDE5 mechanism, combining it with prescription PDE5 inhibitors or nitrates is theoretically risky. Supplement adulteration with undeclared sildenafil is a documented hazard in this product category.
This is something to take to a clinician. The Atlas can tell you what is known about horny goat weed for ed in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
Horny goat weed (Epimedium species) is a traditional Chinese herb whose active constituent, icariin, is a genuine but weak natural phosphodiesterase type 5 inhibitor, the same enzyme target as sildenafil. Evidence in humans is limited to preclinical and small studies; the icariin content of commercial supplements is highly variable, so real-world potency is unpredictable. It is plausible in mechanism but far weaker and less reliable than pharmaceutical PDE5 inhibitors.
Traditional Chinese herb with a real but weak PDE5-inhibiting molecule.
What people take it for
These are the reasons people give for taking it. They are not effects it has been shown to have.
How it is supposed to work
Icariin inhibits phosphodiesterase type 5, the same enzyme blocked by sildenafil, preserving cGMP in penile smooth muscle, but with far lower potency, and the dose delivered by supplements is inconsistent and usually subtherapeutic.
What people get wrong
Often saidHorny goat weed is a natural Viagra that works just as well
ActuallyIcariin is a real but weak PDE5 inhibitor; commercial products are variable and usually far below a therapeutic dose. It is not equivalent to pharmaceutical PDE5 inhibitors.
Who profits, and who pushes back
Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.
At a glance
- Active compound
- Icariin
- Target
- PDE5 (weak)
- Evidence
- Mostly preclinical
- Content variability
- High between products
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Horny Goat Weed for ED. A short entry is not a safe entry.
- Timeline. We have not built the dated record of research and regulatory events.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- Where we land. We have not taken a position on this yet.
Sources
No sources recorded for this entry yet. Nothing on this page can be checked against a citation until that changes, so treat it as a summary awaiting its evidence.