If your erectile dysfunction (ED) drugs don’t work, it doesn’t necessarily mean you’re out of luck.

Many men who fail to respond to ED meds are taking them incorrectly, finds new research from Spain.

In the study, 69 percent of guys who reported that their genitals problems persisted even after taking PDE5 inhibitors, were making some errors when downing the pills.

According to Menshealth, the researchers offered these patients a “re-education” program to help them better understand how they should use the meds. Of the guys that accepted, 77 percent then responded favorably to the ED drugs.

The problem: many men aren’t given enough information on how to use the drug when they’re prescribed it, says Jacob Rajfer, M.D., professor of urology at the David Geffen School of Medicine at UCLA.

See how men commonly misuse ED drugs, and learn from their mistakes.

Don’t expect a miracle.

Most guys know that these meds don’t magically give them a stretched genital.

Still, 3 percent of study participants reported they weren’t getting enough results when trying them out.

If you have not gotten a stretched genital, you might as well have just popped a placebo.

That’s because of how the drug works in your body.

When you get excited for love making, your brain sends a signal via the nerves down to your genitals.

This releases a chemical into the muscle of the genital, which then sparks the production of another chemical, the one your ED meds work on to give you a boner. If you’re not excited, that second chemical wouldn’t form in the first place.

“We tell men not to take the drug and expect miracles happening without doing some work, foreplay, things like that,” says Dr. Rajfer.

Take more than the bare minimum.

Unless you’ve reached the max dosage, don’t assume your meds aren’t going to work for you, an error shared by 31 percent of the study participants.

It might be tempting to start at the lowest dose, who wants to take more medication than they need?

But the reality is, it might not be enough to treat the problem. And that can leave guys frustrated.

“For the majority of men who come in really complaining about ED, if it’s going to work, it’s going to work at the higher dose,” says Dr. Rajfer.

Exception: If you have other health conditions, like hypertension, diabetes, or high cholesterol, your doctor will probably start you on a lower dose to make sure you can tolerate the medication, he says.

Otherwise, ask your doctor if your prescription is for the maximum.

Don’t eat before popping the pill.

If you’ve just had a big dinner, a romp in the bedroom right after might not be in the cards. Over 20 percent of men in the study made the mistake of taking Viagra or Levitra too soon after eating.

That’s a major problem. Those two drugs work best on an empty stomach, so you need to wait at least 2 to 3 hours after a full meal to take them, says Dr. Rajfer.

Wait a little while to have intercourse.

We know you’re eager, but it really does pay to wait. One in six guys in the study screwed up by initiating intercourse too soon after popping the pill.

If you’ve got a script for Viagra or Levitra, you need to wait at least 1 hour before getting busy.

That’s when the drug reaches its peak level in your system, says Dr. Rajfer. Cialis reaches its highest level between 2 to 3 hours after you swallow it.