How Long Does a Penile Injection Last

How Long Does a Penile Injection Last?

How Long Does a Penile Injection Last? The Definitive Answer!

Article Overview

If you’re considering the use of penile injections to solve your symptoms of erectile dysfunction, this guide everything you need to know (including the dangers and negatives) before you start injecting your prick!

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Last updated Last updated 30 August, 2022

How Long Does a Penile Injection Last?

Penile injection therapy isn’t for everyone – the prospect of putting a needle down there is scary, even if it does work! Under some circumstances, however, a penile injection can be very effective for solving erectile dysfunction problems. But how long does a penile injection last?

A typical penile injection using Trimix, Bimix, or any of their component drugs alone can help achieve and maintain an erection for one to two hours. Patients may administer injections up to three times a week, with a full 24-hour period in between injections to reduce side effects.

In this article, I’ll be covering how long penile injections last, how they work, included side effects, and much more relevant info.

Number W IconWhat Is a Penile Injection?

Penile injections are a form of injection therapy designed to treat erectile dysfunction. They contain medication that increases blood flow to the penis and make it possible to get and keep erections for sexual intercourse.

Injectable medications produce spontaneous erections, whereas erections from oral ED drugs may require self-stimulation or sexual foreplay to achieve full erection results.

Penile injections are generally considered a last-ditch effort that is best undertaken after oral medications have proven ineffective. In some cases, oral medications may not be possible because the patient has absorption issues with oral meds – in that case, too, penile injections can be an efficient course of action.

Men with severe ED may not respond favorably to oral drugs, which can necessitate injection therapy. It’s best to take your doctor’s suggestions, as they trained for many years and understand the safest and best ways to go about treating ED.

Yet another reason penile injections can be used is to avoid the negative side effects that some oral ED medications have; some of these include headache, congestion, nausea, and even back pain.

Penile injections are usually a combination of three drugs used together, also called Trimix.

These medications are:

  • Papaverine
  • Phentolamine
  • Prostaglandin E1 or alprostadil

Sometimes, only two of these together are used, and that combination is called Bimix. In other instances, only one of these is used for a penile injection drug. Ask your doctor about which combination of these drugs is most effective for your unique needs.

In simple terms, these drugs work together to relax the smooth muscle of the penis, which in turn increases the size of blood vessels. Larger blood vessels help to get and sustain an erection for sex.

Are Penile Injections Safe?

With the exceptions of some rare side effects, penile injections are a safe and effective solution for treating erectile dysfunction. This study where participants used prostaglandin injections determined that only 11% of men experienced painful or undesirable side effects.

Also, note that the study is from 1996 – since then, drug safety and effectiveness have only risen.

    Letter H IconHow Long Does a Penile Injection Last?

    Trimix injections begin to work and create erections within five to 15 minutes, but sometimes the patient will need sexual foreplay or self-stimulation to achieve a full erection.

    For most men, the medication will help them sustain an erection for between one to two hours, though effects exceeding that time span aren’t out of the question.

    How Often Can You Get a Penile Injection?

    You can perform penile injections up to three times a week, with a full period of 24 hours between each injection. It’s important to note that you should only use the effective dose of your medication, and never more than once a day.

    Long-term usage of penile injections is generally safe as long as you’re observing proper technique and using the medication as prescribed. Any changes in other medications you take should be discussed with your doctor and pharmacist, as sometimes medications can interact and cause negative effects.

      Number H IconHow Do Penile Injections Work?

      Patients are typically provided with the medication, syringes, needles, and alcohol pads necessary to perform their own injections. Normally, a patient will undertake a training session, where partners may optionally attend to learn how to administer the medication.

      Injections can be inserted into the spongy tissue on either side of the penis, taking care to avoid the center where the urethra is. Some people prefer to use auto-injectors that quickly insert, inject medicine, and retract in a single motion – this can reduce psychological hesitation.

      It’s important to learn proper injection techniques because using improper techniques can cause scarring and nodules in the penis, sometimes leading to curvature of the penis.

      Injections are delineated into two steps: preparation and injection.


      In this step, you must prepare the medication and the site of injection. Cleanliness is vital during this time to reduce the chances of infection.


      1. Wash your hands thoroughly with warm water and soap.
      2. Remove the syringe and uncap it, ensuring nothing touches the needle.
      3. Pull back the syringe to around 20 units and insert it into the medication’s cap.
      4. Push the plunger down to release the air in the syringe; this is crucial to remove air and create a vacuum.
      5. Turn the bottle upside-down while holding it and the syringe in place.
      6. Pull the plunger to the prescribed dose, going past it by about five units.
      7. Slowly push the plunger back to the prescribed dose, by one to two units at a time. This helps remove excess air from the syringe.
      8. Remove the syringe from the medicine bottle and tap the side a few times to disperse any remaining air bubbles.
      9. Put the cap back on the syringe and store it in a cool, dry place devoid of sunlight.


      Now that the medication is prepared, it’s time to prepare the injection site and actually inject the medicine.


      1. Pull the penis firmly over either thigh by the head – not the skin, as this stretches the penis.
      2. Clean the penis with an alcohol wipe.
      3. Locate veins along the penis – it’s essential to avoid these during the injection.
      4. Uncap the syringe and inspect it for air bubbles.
      5. Pull the penis taut by the head without twisting or stretching it.
      6. Holding the syringe perpendicular to the penis like a dart, quickly insert it.
      7. Push the plunger down to inject the medication with the index or middle finger.
      8. Remove the syringe quickly; rapid insertion and injection are vital to reduce pain.
      9. Clean the injection site with an alcohol wipe.
      10. Dispose of the syringe in an approved sharps container.

      Following injection, you should apply pressure to the injection site to reduce bleeding and potential swelling. If you neglect to do this, you can experience excessive bleeding, which may even become internal. Too much bleeding after injection can cause scar tissue to form, which if repeated, can turn into painful nodules that can change the shape of your erection.

      Where Do Injections Occur?

      Unlike some medical procedures, penile injections are typically self-administered by the patient in a home setting. The patient and (optionally) a partner must attend two training sessions where proper etiquette, technique, and safety procedures are taught in a controlled setting under medical supervision.

      The actual injection happens in the spongy tissue on the left or right side of the penis – this tissue is called the corpora cavernosa. It’s essential to hit this tissue and not veins – unlike intravenous medication that goes into veins, this injection targets the smooth muscle of the penis.

      It’s also important to not inject into the center of the penis where the urethra lies, or the base where veins tend to cluster.

      Are Penile Injections Painful?

      The idea of putting a needle in the penis is an understandably unnerving idea to many, if not most men. It’s anathema to put anything sharp down there, and usually for good reason.

      If performed correctly, penile injections are no more painful than a flu shot – just a short pinch as the needle is inserted for injection. If you’re unsure about the size of the needle, rest assured: penile injections are performed with relatively tiny, thin needles.

        Number H IconHow Much Do Penile Injections Cost?

        Medication pricing will always vary based on the exact source as well as the formulation used – whether it uses one or more drugs will greatly affect pricing.

        GoodRx estimates that penile injection medication can be bought for as little as $5 per doseexternal link icon. Note that this estimate is for medicine containing only alprostadil.

        Oral medications treating erectile dysfunction virtually always cost $10 to $20 more per dose than injectable drugs, two popular examples being Viagra and Cialis.

        Does Insurance Cover Penile Injections?

        Penile injection medication is not covered by insurance under most circumstances – the only exceptions may be if ED has occurred due to conditions like prostate cancer. This is fairly rare, though, so it’s best to ask your insurance provider about your unique circumstances.

        It’s best to expect that most of the cost of penile injections will come out of pocket.

          Letter W IconWhat Is the Success Rate of Penile Injections?

          When thinking about any medication, it’s important to thoroughly research just how effective it is – this is especially the case when you’re talking about sticking a needle in your penis! Most men start off on oral ED drugs, and according to Broward Urologyexternal link icon, they work for about 80% of cases. The same is true of penile injections.

          The Urology Department at UCSF says penile injections are effective for over 80% of menexternal link icon. Effective in this circumstance means that most patients get a functional and satisfactory erection suitable for sex.

          It’s also mentioned that for best results, proper doses as determined by your doctor must be used. If changes are made to the dose, like reducing or increasing it, you’re more likely to experience undesirable side effects or not get your desired results.

            Letter D IconDo Penile Injections Increase Size?

            Using Trimix or its component drugs will not increase the size of your penis, contrary to popular rumors. Neither Trimix, Bimix, or any of the ingredients in them are designed to increase the length or girth of your penis.

              Letter W IconWhen To Consider Penile Injections

              For most men, injection therapy for erectile dysfunction is not the first treatment option. Usually, doctors will recommend and prescribe oral medications before they suggest injection therapy.

              If results aren’t achieved with oral medication alone, or such medications produce undesirable side effects, doctors may recommend injection therapy.

              Here are some reasons to consider penile injections:

              • Oral meds like Viagra or Cialis produce negative side effects (headache, congestion, nausea, back pain, etc.).
              • You get no improvement from oral medication.
              • You are on medication that interferes with oral ED drugs.

              How To Get a Prescription for Penile Injections

              Before getting a prescription for penile injection drugs, your doctor will have to formally diagnose you with erectile dysfunction. Next, they will most likely recommend you try oral medications to treat ED. This is because, for most men, oral drugs are effective. Not to mention, needles are intimidating!

              If for some reason you get negative effects from oral meds or they don’t work, your doctor can write you a prescription for penile injection medication. This prescription can be filled at any licensed pharmacy, whether a brick-and-mortar location or a licensed online pharmacy.

              Either one can directly ship the drugs and injection kit to your home if you are shy about filling the prescription in person.

                Letter C IconCan You Use Penile Injection With Oral ED Medication?

                You should never use penile injections in combination with oral ED drugs like Viagra or Cialis because they both perform the same basic action: relax and dilate the penis so blood vessels can fill with blood. If used in combination, you risk priapism.

                Priapism is a dangerous condition where the penis stays erect for extended periods of time when blood can’t drain. Priapism can lead to penile scarring and in some cases, permanent erectile dysfunction.

                If your doctor has given you the green light to use both at different times, take care: Never use injectable ED drugs within 18 hours before or after taking oral drugs.

                If penile injections alone aren’t helping you achieve an erection, you should talk to your doctor about adjusting your dosage – never combine oral drugs with injectables just because you aren’t getting the desired results.

                If oral ED drugs did not help you and your doctor prescribed injectables, it’s best to dispose of your oral medication at a pharmacy or doctor’s office.

                Do Other Drugs Interact With Penile Injections?

                As with any drug, it’s important to tell your doctor about any medications you’re on.

                Penile injections are safe to use with most meds; nitroglycerin is a rare exception. Nitroglycerin has historically been used for heart conditions, but recently, its potential as an ED treatment has been realized. As such, you shouldn’t take nitroglycerin in conjunction with penile injections.

                If you’re unsure, ask your doctor or pharmacist if you are okay.

                  Letter W IconWhat Side Effects Do Penile Injections Have?

                  Penile injections may be effective and generally safe, but like any drug, they’re not without the risk of side effects.

                  The most common side effect of penile injections is some minor bruising and bleeding at the injection site, especially if proper injection technique isn’t used. Infection can also happen if the site isn’t thoroughly cleaned before and after injection.

                  Other possible side effects of penile injections include:

                  • Dizziness
                  • Fainting
                  • Low blood pressure
                  • Mild pain immediately following injection
                  • Reduced sensation or difficulty achieving climax
                  • Scarring, especially if too much medication is used
                  • Priapism, or an erection lasting longer than usual

                  Priapism is the most serious known side effect, and it is especially serious if the erection lasts for four hours or more. Taking a decongestant such as phenylephrine in combination with applying an ice pack to the penis can help reduce swelling. If the erection lasts for more than four hours, immediately seek medical attention.

                  Similarly, if you experience abnormal pain or bleeding for more than a few minutes, seek a doctor to address the problem. If you performed the injection improperly and hit a vein by mistake, this could be the cause of excessive pain and/or bleeding.

                    Letter T IconThe P-Shot: How It’s Different From Penile Injections

                    Trimix and similar medications are injected every time you wish to get an erection, but there exists an alternative to these: the P-Shot, also known as PRP (platelet-rich plasma) therapy.

                    The P-Shot is derived from the patient’s own blood, which is put into a centrifuge and spun at high speeds to separate the plasma from the red blood cells or hemoglobin. The plasma and platelet portion of the blood is then injected into the penis.

                    The main difference is that the P-Shot does not have to be repeated every time you want to get an erection, unlike Trimix and its component drugs. The P-Shot can take as long as one to six weeks to notice improvement on erections, but the results can last as long as two years before another injection is needed.

                      Letter F IconFinal Thoughts

                      Penile injections are a rather drastic and daunting answer to erectile dysfunction, but all research shows they are relatively safe and effective. With proper guidance, you can achieve and maintain an erection for one to two hours per injection.

                        This Content Was Written By...

                        Author & Site Owner | Website
                        Chris is the owner and creator of Penis Enlargement Resource. He has years of knowledge in the male enhancement niche and has tested and assessed numerous products over the years.

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                        Chris Sabian Author & Site Owner

                        Avatar of Chris Sabian

                        So I’m Chris Sabian, the creator and owner of the Penis Enlargement Resource website.

                        Now I’m going to be honest, I’m actually really happy with the size of my penis – i’ve never had any complaints, and it works exactly how it’s meant to.

                        That said however, I have worked for various companies and businesses within the men’s sexual health niche – it’s from these years of experience actually working on a number of different products that i have an absolute wealth of knowledge on what does and doesn’t work.

                        Yes natural penis enlargement IS possible but the amount of bullshit out there is phenomenal.

                        In some cases, even doctors don’t know what is truly possible, with many (especially in the US) simply prescribing treatment options that are the most profitable for their clinics!

                        The number of times I’ve seen adverts online for this miracle cure for erectile dysfunction, or a product claiming to give you 3 more inches in less than a month really does play in to the unrealistic and misguided view point of so many and that is why i created Penis Enlargement Resource – to stop the scare mongering and provide a completely unbiased view point on every product that passes my desk.

                        Yes! Every product i review i actually have possession of – i’m not simply writing reviews based on other generic online content, so if your reading a review and can’t see any unique photos or videos, chances are it’s just an affiliate marketer trying to make a quick buck off your insecurities.

                        So take a step back, read the articles I’ve written and see which products I’d REALLY recommend, so you can take that first step towards making your penis bigger, stronger or harder.

                        The journey to natural penis enlargement is not a fast process, it is not an easy process… but if you stick with it, i absolutely promise you, it IS possible.


                        This Content Was Written By...

                        Author & Site Owner | Website
                        Chris is the owner and creator of Penis Enlargement Resource. He has years of knowledge in the male enhancement niche and has tested and assessed numerous products over the years.

                        Content By This Author...

                        Questions & Comments

                        2 Replies to “How Long Does a Penile Injection Last”

                        1. Can you lose an erection after ejaculation when using penile injection. What if you suffer from PE also?

                          • Yes is the answer. To be fair most men, especially as you get older will struggle to maintain an erection after ejaculation however obviously everyone is different and respond to different stimulation in varied ways. A good option is a cock ring; wearing one of these will allow you to maintain an erection for longer (potentially even after ejaculation) and could also help you manage symptoms of premature ejaculation (PE).

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