Two ways to use ED medicine
PDE5 inhibitors for erectile dysfunction (ED) can be used in two main ways. “On-demand” means taking a dose at a suitable time before sex. “Daily” means taking low-dose tadalafil at the same time every day so there is a steady level of the medicine in the body.[1]
These are different approaches; neither is automatically stronger or better for everyone. The right choice depends on how often you are sexually active, your relationship, other health conditions, side effects and cost.[1]
Why the schedule matters
Many men using on-demand treatment feel they have to “plan” intimacy. Thinking about when to take a tablet can make sex feel less natural, or add worry about whether it will work in time. For some men, switching to daily treatment removes that time pressure and lets intimacy feel spontaneous again.[1]
On the other hand, men who have sex only occasionally may not need a daily tablet. Choosing the right approach reduces unnecessary medication and cost.
Who tends to use each approach
Both are treatment options for ED, not separate conditions, and use depends on access and individual suitability.[1] In practice, men who are sexually active several times a week, or who dislike planning around a dose, often consider daily treatment, while men with occasional activity are often happy with on-demand use.
Low-dose daily tadalafil is also used to treat urinary symptoms from an enlarged prostate. Men with both ED and urinary symptoms may therefore benefit in two ways from one medicine, following medical assessment.[1]
How each approach works
PDE5 inhibitors block the enzyme that breaks down cGMP, the messenger that widens penile blood vessels during sexual stimulation.[1],[2]
- On-demand: levels are high for a few hours after a dose. Sildenafil starts working in about 30–60 minutes, while tadalafil's window of effect lasts up to 36 hours.[1]
- Daily: tadalafil 2.5 or 5 mg is taken at the same time each day. Levels build to a steady state within a few days, so the body is ready to respond at any time.[1]
Neither approach causes a continuous erection, and both still require sexual stimulation.
What your doctor reviews before choosing
Your doctor checks for contraindications, especially nitrates and nicorandil, and reviews heart health, kidney and liver function, and other medicines.[1],[2] You will also be asked how often you are sexually active, whether you have urinary symptoms, what side effects you have had and how previous treatment went.
Importantly, if on-demand treatment seemed not to work, your doctor will first check whether it was used correctly: taken at the right time, not after a heavy fatty meal for sildenafil, with enough stimulation, and tried several times, before deciding a different approach is needed.[1]
Advantages and limits of each
On-demand lets you take medicine only when you need it, usually costs less for men with occasional activity, and is easy to stop. Its limitation is the need to think about timing and food, which some men find stressful.
Daily removes the need to plan, allows more spontaneous intimacy, and can help prostate-related urinary symptoms in some men. Its limitations are taking a tablet every day, potentially higher total cost, and continuous exposure even on days without sex.[1],[2]
Whichever you choose, review it after a fair trial of correct use, looking at effectiveness, side effects, convenience and cost. Do not add an on-demand dose to daily treatment yourself, and if the response is not enough, see your doctor rather than increasing the dose on your own.[1],[2]
How we care for you at Dr. Kris Clinic
We help you choose a schedule that fits your real life, not a one-size-fits-all formula. We ask about how often you are active, your work schedule, your relationship and what cost is acceptable, together with heart safety and current medicines, in English or Thai.
After you start, we follow up to see whether the approach really suits you, and it can be changed at any time. Many men start on demand and move to daily treatment, or the reverse, as life changes.
Frequently asked questions
Will I become resistant if I take it every day?
There is no evidence that these medicines lose effect with continued use. If the effect seems weaker, other factors such as progressing vascular disease or stress should be checked.
I take a daily dose. Can I add a tablet before sex?
Not on your own. If the effect is not enough, ask your doctor to review how you use it and whether treatment should change.
What if I miss a daily dose?
Take the next dose at the usual time. Do not double up.
When can I stop daily treatment?
Whenever you wish, after discussing it with your doctor. These medicines do not cause withdrawal symptoms.
Daily and on-demand treatment differ in how they are used, not in strength. Choose together with your doctor and review the response after an appropriate trial of correct use.[1]
Talk to a doctor about this
Confidential care in Surat Thani, the mainland gateway to Koh Samui, Koh Phangan and Koh Tao. Tue–Fri 17:00–20:00 · Sat–Sun 10:00–15:00 (UTC+7)
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Dr. Krida Uakridathikarn (Dr. Kris)
Board-certified family physician with certificate training in clinical sexology and sexual medicine. He works at Suratthani Hospital and provides sexual health, hormone and LGBTQ+ inclusive care at Dr. Kris Clinic. Profile and CV
References
- EAU Guidelines 2026: Management of Erectile Dysfunction
- EAU Patient Information: Medicines for ED (2026)
- Chung et al. USANZ/AChSHM ED guideline. Med J Aust. 2022;217:318–324. doi:10.5694/mja2.51694
Keep reading
Main guide: Men's sexual health
Erectile Dysfunction (ED): Causes, Tests and Treatments That Work
Erections and Heart Health: Why ED Can Be an Early Warning Sign
What Morning Erections Tell You About Your HealthThis article is general education, not personal medical advice or a promise of results. Diagnosis and treatment require assessment by a doctor. Content reflects the cited sources as of the update date.