Sildenafil was launched in 1998 and PDE5 inhibitors have since been among the most widely used medicines in the world. NHS community prescribing of sildenafil in England nearly tripled across a decade, reaching close to three million items a year.
That scale of use over that length of time means the safety profile is unusually well characterised. Long-term use in appropriately assessed people is generally regarded as safe.
Does Tolerance Develop?
Not in the pharmacological sense. PDE5 inhibitors do not lose effect through tolerance the way some medicines do.
What does happen is that the underlying condition progresses. If ED is caused by vascular disease or diabetes, and that condition worsens, the same dose delivers less. That feels like tolerance and is treated quite differently — the answer is to look at the underlying cause, not simply to escalate the dose indefinitely.
Dependence
These medicines are not addictive and do not cause physical dependence. There is a recognised psychological pattern where someone becomes reluctant to attempt sex without one, particularly after a bad experience. That is worth naming and is treatable — it responds to psychosexual approaches rather than to a different tablet.
The Genuine Long-Term Considerations
Cardiovascular
These medicines lower blood pressure modestly. In people properly assessed, that is fine. The risk lies in taking them without assessment, or alongside nitrates — which is why buying from a source that asks nothing is the actual danger rather than the duration of use.
Vision and hearing
Sudden loss of vision or hearing has been reported rarely and warrants immediate medical attention. Rare, but worth recognising.
Priapism
An erection lasting more than four hours is a medical emergency requiring urgent treatment, because prolonged priapism can cause permanent damage. Rare with oral PDE5 inhibitors, more associated with injectable treatments, and more likely in certain conditions such as sickle cell disease.
What Should Be Reviewed Periodically
Long-term use is a reason for periodic review rather than indefinite repeat supply:
- Blood pressure
- Cardiovascular risk, including cholesterol and glucose
- Whether other medicines you take have changed — particularly any new nitrate
- Whether the underlying cause of the ED has been investigated at all
That last point is the one most often skipped. Someone who has bought sildenafil online for five years without a single clinical review has an unexamined cardiovascular question sitting underneath a well-managed symptom.
Daily Dosing
Low-dose daily tadalafil is licensed and is a legitimate long-term approach. It suits people who dislike planning around a tablet, and it is also used for benign prostatic hyperplasia symptoms, so some men get two benefits from one prescription. It is not more risky than on-demand use.
The Cost Angle
If you are going to take something for years, price it per year at the quantity you actually use. Generic sildenafil is inexpensive; regular use of avanafil is not. And check periodically — this is a competitive market and the cheapest legitimate supplier changes.
What is not a saving is an unregulated supplier. The MHRA seized roughly 19.5 million doses of illegal ED medicines across five years, including pills with no active ingredient, the wrong dose, or contaminants. Long-term use of something you cannot verify is the actual long-term safety problem.