What do IIEF and SEP actually cost me as a patient, in plain words?
What an IIEF point costs that a comment never will
The first thing the sildenafil programme bought was a way to score a private complaint. Without that, 25-100 mg would still be anecdote.
The International Index of Erectile Function is a questionnaire, not a vibe. It scores erectile function, orgasm, desire, intercourse satisfaction, and overall satisfaction. Two items carried the approval weight: ability to get an erection sufficient for intercourse, and ability to keep it after penetration. Answers run from 0 (no attempt) through 5 (almost always). A man filled those for the last four weeks of double-blind treatment after a four-week treatment-free run-in. That is a slow, slightly awkward instrument. It is also why a trial can be repeated.
The Sexual Encounter Profile is even blunter. After each attempt, a man logs whether he got an erection and whether he held it long enough for satisfactory sex. SEP2 and SEP3 still sit under later PDE5 trials. A yes or a no, tallied against placebo across hundreds of men, is a number a forum cannot mint. Sildenafil's US licence stood on that kind of count. The mechanism those scores ride is in the sildenafil signal note.
Goldstein 1998: 25, 50, and 100 mg on a scored ladder
Ping the paper, not the meme. Irwin Goldstein and colleagues reported two sequential double-blind studies in the New England Journal of Medicine in May 1998.
| Study | N | Design | Signal worth keeping |
|---|---|---|---|
| Dose-response, 24 weeks | 532 | Fixed 25 / 50 / 100 mg vs placebo | IIEF achieve/maintain rose with dose; 100 mg: 4.0 vs 2.0 baseline |
| Flexible, 12 weeks | 329 | Climb toward 100 mg | 69% vs 22% successful attempts; 5.9 vs 1.5 per month |
| Open-label extension | 225 of 329 | 32 weeks | 92% completed |
The dose-response study ran 24 weeks in 532 men with organic, psychogenic, or mixed erectile dysfunction. Arms were placebo or oral sildenafil at 25, 50, or 100 mg. Rising dose tracked rising scores on the two IIEF questions about achieving and maintaining erections. At 100 mg, the mean score for achieving an erection doubled from a baseline of 2.0 to 4.0 on a 5-point item. That is a clean ladder, not a single lucky arm.
The flexible study ran 12 weeks in 329 different men, starting and then climbing toward 100 mg on efficacy and tolerance. In the last four weeks, 69 percent of intercourse attempts succeeded on sildenafil against 22 percent on placebo. Successful attempts per month averaged 5.9 versus 1.5. Headache, flushing, and dyspepsia sat between 6 and 18 percent in that climb. Two hundred twenty-five of the 329 entered a 32-week open-label extension; 92 percent finished it. Those are the numbers a 'it worked for my cousin' post is trying to impersonate.
A diary beat a thread about a cousin
Forum lore collapses three different facts into one shout. 'It works' might mean a global yes on a single night. '69 percent' might mean that man thinks he is in Goldstein's last four weeks. '100 mg is the real dose' might mean he never sat on 25 mg long enough to see a side-effect flag. The diary does not allow that collapse. Each attempt is a row. Each dose is an arm. Placebo is in the room, and placebo already delivered 22 percent successful attempts. That 22 percent is the part reviews skip, because it makes the drug look less like magic.
The labelled usual start is still 50 mg about an hour before sex, movable to 100 mg or down to 25 mg. This desk's SERP lock is 25 or 100 mg because those are the edges a man actually fights over after a first disappointing night. The ceiling is one dose in 24 hours. Stimulation is required, because the scores measure an amplified signal, not a manufactured one. How to time that swallow against a plate is in the clock-and-plate guide.
Who the 25 mg start is written for
A lower tablet is not a lesser man. It is a labelled response to higher exposure.
The US label tells you when to open at 25 mg. Age over 65. Hepatic impairment such as cirrhosis. Severe renal impairment, creatinine clearance under 30 mL/min. Strong CYP3A4 inhibitors - ketoconazole, itraconazole, saquinavir - or erythromycin, which raised levels about three-fold. Alpha-blocker users who are already stable on that blocker. Ritonavir is in a class of its own: 11-fold AUC, so the cap is 25 mg in 48 hours, not a cheap daily 100 mg.
Those are exposure flags, not moral ones. Older clearance, a sick liver, a sick kidney, or a stacked CYP3A4 inhibitor all leave more citrate in the blood. Starting at 100 mg in that room is how you buy a pounding headache and a faint, not a better IIEF. Titrate up if the 25 mg night is honest and quiet. Do not let a forum talk you into the ceiling because 'trial cost' sounded like 'more milligrams bought more manhood.'
SUPER-1 walked 45 metres; that is not an ED score
| Card | What was scored | What it does not buy |
|---|---|---|
| Goldstein ED | IIEF items, attempt diaries, 25-100 mg as needed | A lung walk, a daily 20 mg habit |
| SUPER-1 PAH | 6-minute walk, mPAP, WHO class, 20/40/80 mg TID | An IIEF point, a cheap 100 mg evening |
Galiè and the SUPER Study Group randomised 278 adults with symptomatic pulmonary arterial hypertension - idiopathic, connective-tissue, or repaired congenital shunts - to placebo or sildenafil 20, 40, or 80 mg three times daily for 12 weeks. The primary endpoint was change in six-minute walk distance. Placebo-corrected gains at week 12 were 45, 46, and 50 metres. Mean pulmonary-artery pressure fell. WHO functional class improved. The study was not powered for death. Among 222 people who completed a year on monotherapy, the walk gain from baseline was 51 metres.
Here is the flag. Walk distance barely separated 20 mg from 80 mg. Haemodynamics moved a little more at the top. Side effects - flushing, dyspepsia, diarrhoea - climbed with dose. So the approved Revatio dose was 20 mg three times daily, the lowest effective walk dose, not the highest tolerated one. That card does not set your evening 25-100 mg. It does prove the citrate is a real pressure drug, which is exactly why a nitrate next to any of those strengths is not a casual stack. The origin of both files is in the Sandwich file note.
Diabetes and nerve-spare: where the ladder shortens
An honest read includes the rooms where 25-100 mg helps less. That is where forums over-promise and then call the tablet a dud.
Men with diabetes often carry both small-vessel and nerve damage. Response rates run lower than in men whose erectile failure has no clear physical cause. Many still improve, especially if they give 100 mg a few honest, stimulated attempts rather than one anxious night. After radical prostatectomy the story is harsher. If the cavernous nerves were spared, there is a signal left to amplify. If they were cut, the tablet has less to work with. The drug does not grow a nerve. It preserves cyclic GMP when nitric oxide arrives.
None of that makes a 25-100 mg trial a waste in those rooms. It makes the conversation adult. Several attempts. Decent timing. A willingness to move to injections or a device if pills stay flat. Safety framing does not loosen because the efficacy number is smaller: no nitrates, review other pressure drugs, start at 25 mg when age or CYP3A4 already shout. Tadalafil and vardenafil sit on the same enzyme and the same hold. They do not rescue a missing nerve either.
Cheap generic 25-100 mg does not cheapen the endpoint
Once the patents lapsed, the receipt shrank. The IIEF did not. A licensed generic 25 or 100 mg tablet has to deliver the same citrate into blood. What it does not have to do is reprint Goldstein in the box. That is why a man can buy a cheap blister and still need the same scored expectations: stimulation, a clock, a food flag, one dose per day, a 25 mg start when the label says so. Price is not an endpoint.
Reviews that treat 'cheap' as 'weaker' and '100 mg' as 'the real trial' are spending lore. Goldstein's ladder included 25 mg. The flexible study climbed. Placebo already cleared 22 percent of attempts. If a cheap tablet 'fails' after a fry-up and a five-minute wait, you have not spent the trial cost. You have spent a night. How to spend the night correctly is in the clock-and-plate guide.
Post: keep the score, drop the lore
Post this. 25-100 mg beat placebo on IIEF and on diaries, with a dose-response Goldstein actually published. 69 percent versus 22 percent is a last-four-weeks attempt figure, not a personality. SUPER-1 is metres on a three-times-daily lung dose. Diabetes and nerve injury shorten the ladder. Cheap generics change the receipt.
The holds that came with those scores are not footnotes. No nitrates. No riociguat. Stimulation required. One swallow in 24 hours, or 25 mg in 48 hours on ritonavir. Take the score to a clinician who has your list before you change a tablet. The desk disclaimer is the last stamp on this page, not a decoration.
Reader mail
Reader questions on this article
Answered by Dr. Elena Vasquez, MD · Urology & men's health
After the scorecard, readers wanted the numbers translated without the forum accent. Nine named questions.
They cost you honesty and a few weeks, not money at a checkout. IIEF is a questionnaire about whether you can get and keep an erection, plus desire and satisfaction. SEP is a diary: after each attempt, yes or no on getting it, yes or no on holding it. Trials used those so 25-100 mg could be compared with placebo instead of with a cousin. When a review shouts a percentage, ask which instrument and which week. If the poster cannot say, it is lore. The labelled tablet in the sildenafil signal note still sits on those instruments.
I keep seeing 69 percent. Is that my chance on 100 mg?
No. That figure is from Goldstein's flexible 12-week study: in the last four weeks, 69 percent of attempts succeeded on sildenafil versus 22 percent on placebo. It is not a promise that you, personally, have a 69 percent personality. It is also not a 100 mg-only number; men in that arm climbed by response and tolerance. Placebo already cleared about one in five attempts, which is the part forums drop. Your number depends on nerves, vessels, diabetes, timing, and whether you actually stimulated. A cheap generic does not mint a new percentage.
Should I open at 25 mg or jump to 100 mg because the trial ladder went there?
Open where the label points, not where a thread sounds braver. Most men start at 50 mg about an hour before sex. This desk talks 25 or 100 mg because those are the edges: 25 mg if you are over 65, have a sick liver or a creatinine clearance under 30, take a strong CYP3A4 inhibitor, or are stable on an alpha-blocker; 100 mg if 50 mg was honest, tolerated, and still short. Ritonavir is 25 mg in 48 hours. Jumping to 100 mg to 'match the trial' is how you buy a headache, not an IIEF point.
SUPER-1 keeps coming up. I do not have lung disease. Why should I care?
Because it proves the citrate drops pressure in real vessels, not only in a bedroom story. 278 people, 12 weeks, 20, 40, or 80 mg three times daily. Walk distance rose about 45 to 50 metres against placebo at all three doses, so 20 mg three times daily became Revatio. If you only care about 25-100 mg at night, keep one fact: this is a cardiovascular drug. That is why a nitrate next to it is not a spacing trick. Do not spend SUPER-1 metres on an ED dose, and do not spend an ED diamond on PAH.
Diabetes. Will 25-100 mg look like Goldstein in my house?
Usually not as clean. Diabetes chews small vessels and nerves, so there is less nitric-oxide ping for the tablet to preserve. Many men with diabetes still get a usable night, more often at 100 mg after several timed, stimulated attempts than after one angry try on 25 mg. If pills stay flat after a fair run, say so. Injections exist. And the hold tightens, not loosens, because diabetes often travels with heart disease: no nitrates, a real medicine review, a 25 mg start if the kidney or an interacting drug is already in the room.
Does a cheap generic 25-100 mg tablet score lower than brand in the trials?
The Goldstein pair was brand-era sildenafil citrate. A licensed generic has to match the active drug and the blood delivery, not reprint 1998 in a new journal. There is no honest IIEF that says 'cheap equals weaker.' There is a very honest failure mode where a man buys a cheap blister, swallows it after a fry-up, waits five minutes, and posts that generics are duds. That post did not pay the trial cost. It paid a plate. Use a real pharmacy. Keep the clock. Then judge the milligram.
Cialis and Levitra keep getting named under these scores. Is one 'better'?
On raw erectile scores the three land in the same neighbourhood. The bill that differs is time and food. Sildenafil, 25-100 mg, works on a few-hour clock and hates a fatty meal. Vardenafil tracks that clock. Tadalafil lasts up to about 36 hours and mostly ignores dinner, and it can be a small daily tablet. 'Better' is a fit word, not a potency word. The hold is identical: no nitrates on any of them. Read tadalafil and vardenafil as separate files, not as forum nicknames for 'stronger.'
The tablet did nothing on its own. Did I get a dud, or did I misread the endpoint?
You misread the endpoint, unless the blister is fake. IIEF and SEP assume sexual stimulation. Sildenafil preserves cyclic GMP after nitric oxide arrives. No arousal, no arrival, no score. That is a safety feature as much as a limitation - you do not walk around with an unwanted erection. A fair test is a timed swallow, a reasonably empty gut, a real attempt, and a few nights before you call 25 mg or 100 mg a failure. Anxiety on night one is not a protocol violation. It is the usual confounder.
Where is the trial file if I do not trust a journal blog?
Goldstein I et al., N Engl J Med 1998;338:1397-404, is the ED pair. Galiè N et al., N Engl J Med 2005;353:2148-57, is SUPER-1. The US label restates the 21 randomised ED trials and the 25, 50, 100 mg ladder. I point patients at FDA and DailyMed rather than at a screenshot of a comment. This page is a reading of those stamps, not a substitute for a clinician who has your nitrate list. The desk disclaimer is there for that reason.
General education from a clinician, not personal medical advice. Bring your own history to your own prescriber.
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