Guide: Penile Injections for Erectile Dysfunction

What is a penile injection?

A penile injection, as we briefly covered in our article on the 5 most popular types of male enhancement surgery, is a clinical method used to temporarily resolve the symptoms of erectile dysfunction.

The emphasis is on temporarily as taking a penile injection will not cure or permanently resolve your symptoms of erectile dysfunction, only mask them for a predefined period of time.

Using a very thin, fine needle (which means discomfort is reduced to the absolute minimum), a specific amount of medication is injected into the corpus cavernosum vein which is located in the penis.

This vein controls the blood flow to the penis and by taking a penile injection allows the vein to relax and carry more blood hence allowing erections to be achieved by those who perhaps struggle to gain arousal or whom suffer from either psychological or physical erectile dysfunction.

What does a penile injection contain?

There are two main types of solution used for penile injections – Alprostadil (sometimes also referred to as Caverject or Edex) and TriMix.

Alprostadil (also referred to Prostaglandin ED – PGE1) is a naturally occurring liquid that has a very diverse hormone enhancing effect. In the case of erectile dysfunction it is available as a urethral suppository or administered by injecting slowly into the penis.

When injected, the fast acting solution allows the corpus cavernosum vein to relax and as a result better fill with blood hence allowing an erection to be more easily attained.

TriMix is a more expensive “branded” version of Alprostadil and although isn’t necessarily stronger (some have suggested in terms of results it’s marginally weaker than Alprostadil) has been shown to produce far less discomfort where aches and pain are concerned.

Generally Alprostadil will be prescribed first and then if comfort or results aren’t achieved, TriMix will then be considered.

The active ingredients in TriMix – which give it it’s three-drug classification, hence a comparable dosage doesn’t contain as much solution as the Alprostadil exclusive version – include Alprostadil as well as Papaverine and Phentolamine which further help to relax and smooth the blood vessels of the penis further allowing the corpus cavernosum to better fill with blood allowing for an erection to be achieved.

How to do a penile injection

  1. Prepare the injection based on the medical advice provided to you by your consultant or medical professional.Ensure you have the correct dosage of medication in the syringe is essential – too little and you won’t attain the results you’re hoping for, whilst too much can potentially have somewhat dire and severe consequences.

    If you feel you’re going to struggle actually preparing the syringe with the correct amount of medication, it is now possible to obtain pre-filled syringes hence reducing the margin of error.

    Once the syringe is ready, place it on a sterile surface with the cap removed.

  2. If you have frozen your supply of Alprostadil (or whichever drug therapy you’ve opted for), ensure it has ample time to defrost – once thawed give the solution a good shake (whilst its still in the vile and not in the syringe).In the event you’re taking the injectable solution from the fridge, take your injection as soon as possible as the longer it remains at room temperature, the less effective the dosage will be.

    Notably the appearance of your medication should never change – it should always be clear/translucent (never cloudy). Also check the expiry date on the bottle.

  3. Now firmly grasp the head of your penis whilst it’s in a flaccid state and gently pull the penis outward (do not twist), away from your body allowing for the sides of the penis to be clearly visible and accessible.It is entirely up to you whether you sit or stand whilst you do the injection (if you’re doing injection for the first few times, many find that sitting is more comfortable and relaxing) however once you get used to the process you may find that by standing you yield better results as this allows your body to better circulate your blood.
  4. We now need to prepare the injection site to ensure it is clean and sterile before actually administering the medication.During this entire build up to taking the injection it’s very important to ensure that the needle remain sterile and the skin where you’re going to inject is also clean otherwise you do run the increased risk of getting an infection.

    To clean the injection site you can either swab the area with alcohol or use an antibacterial wipe – ultimately is best to follow the directions of your doctor.

  5. Carefully choose an area of the penis to use as an injection site. It’s very important that you inject into the side of the penis as this is where the corpus cavernosum vein that we want to stimulate is located.Never inject into the top, underside or tip of the penis whilst also ensuring you avoid injecting into any nerves or blood vessels.

    To improve comfort and to reduce bruising and swelling, make sure that you alternate the side of the penis you inject in – if your last injection was on the left side of your penis, this time use the right side and vice versa.

  6. Now keeping the head of the penis grasped, press the needle to the swabbed/clean area of skin on the penile shaft and firmly (but not forcefully) insert the needle by approximately one centimetre at a marginal 10 o’clock or 2 o’clock angle rather than a 90 degree angle.Once inserted, carefully push down on the plunger to administer the dosage.

    If you don’t feel comfortable doing the injection yourself, you can obviously have your partner do the injection for you – needless to say holding your penis and trying to hold the syringe and injecting solution can take quite a bit of practice.

  7. Having injected yourself with the correct dosage of solution, immediately withdraw the needle (do not twist or jerk as this will increase the chances of bruising) and at the earliest opportunity place the used needle in the provided sharps bin.With the needle removed, then use a further sterile swab to apply light but firm pressure to the injection site.

    This should be done just in case there is any light bleeding as a result of the injection and is even more important for those who are on blood thinners where you should apply pressure for between 5 to 10 minutes to ensure effective clotting.

    In the rare and unlikely event that bleeding persists after 10 minutes of pressure being applied, you should seek medical attention as quickly as possible.


Penile Injection Video

Not for the faint of heart (and likely to make you cringe and cross your legs) – check out a rather insightful video that shows an actual penile injection being carried out.


How long does a penile injection last?

In much the same way as prescription strength erectile drugs such as Viagra, penile injections work in a similar way but are generally vastly more effective given the dosage is administered directly to the penis.

Where pills are concerned, before they start to effectively work a lot of the nutrients and ingredients tend to dissipate as the drugs get absorbed into your digestive system – given penile injections are injected directly where the results are wanted this means the results are generally a lot quicker and usually a lot more effective.

Once the injection has been taken it can take anywhere from 10 to 30 minutes for the effects to be felt, whilst the level of arousal can remain for approximately one hour or until an orgasm has occurred.

As with all types of medication and depending on the dosage of medication you’re given by your specialist consultant, how quickly and how long the results last for will vary person to person however these timescales are generally the norm for penile injections.

How do i know if i’ve used a big enough dose?

Although your consultant will recommend a starting dosage for your injections, it is possible to gradually increase or decrease your dosage depending on the results you achieve however this should only be done when discussed and agreed with your consultant.

In the first few injections you may find that the dosage needs to be increased as although an erection is attained, the strength of that erection perhaps isn’t quite substantial enough to allow for penetration.

Where erectile dysfunction is concerned, an erection hardness score (or EHS) is used to evaluate the strength of a man’s ability or inability to gain and maintain an erection. You may also be asked to keep a record of your arousal levels based on the erection scale. This is where you categorise the level of erection on a scale of 1 to 10.

As you can see a score of 0 to 5 would likely require an increase in dosage, whilst a score of 6 to 10 illustrates that the dosage is correct or potentially even needs to be reduced slightly.

Is quite important that you keep a record of each injection and how effective it was based on the erection scale – this will ensure you’re getting the level of results you need and will also allow your consultant to increase or decrease your dosage as required.

Arousal level erection scale
Arousal level erection scale

How expensive is penile injection therapy?

The cost of a per dosage penile injection will invariably differ depending on location, the type of injection solution (the compounding pharmacy) used and the amount of solution (defined by your consultant) required to attain the desired results.

As a general ballpark figure, in the United States we’re talking on average around $2.25 per injection however the cost to consumer can be significantly higher depending on the specific brand and source of the drugs.

By comparison prescription strength drugs for erectile dysfunction cost roughly between $20 to $40 per dose so it’s easy to see the cost benefit of choosing penile injections over the likes of Viagra another mainstream branded impotence pills.

It’s notable that you don’t just buy a single shot of solution but a large amount which generally costs in excess of $100 – again the overall cost will be determined by where and how you source your supply.

How should i store Alprostadil or TriMix penile injections?

The two most common types of penile injection solution – Alprostadil and TriMix – must both be stored in a fridge so that the solution does not rise above a specified temperature – namely 4 degrees C or below.

Failure to keep the solution refrigerated, or leaving the injection solution at room temperature for too longer period prior to injection, can cause the enzymes in the solution to become ineffective ultimately meaning the injections will not produce as sufficient results as you would like.

Of both the solutions, Alprostadil is notably the least stable of the two drugs (as detailed in this study from 2004) meaning that even when refrigerated it has a generally lower shelf life when compared to its branded alternative TriMix.

In both cases however, Alprostadil and TriMix can be frozen (for up to six months) and then thawed fully (and shaken well) prior to usage to further prolong the active ingredients lifecycle.

If you’re not planning on using the penile injections within the space of 1 month or less, freezing your supply of Alprostadil or TriMix would be the recommended and preferred method for storage.

Does a penile injection hurt?

It’s worth remembering that when actually doing a penile injection, you are injecting into a flaccid penis (rather than an erect penis). As a result the skin of the penis is a lot looser and flexible not to mention the fact the penis is not filled with blood at this stage and as a result is not rigid.

This means that when injecting you should only feel a slight scratch as you insert the very thin needle approximately 1cm into the skin.

Depending on the frequency that you decide to take penile injections, you shouldn’t experience any long-term pain however in some instances men do experience some aching pain at the location of the injection for up to 60 minutes following the injection being undertaken.

How many penile injections can i take each day/week/month?

Clinically speaking, at the most, you should only take one injection every 24 hour whilst it is also recommended that you do not exceed more than 10 injections in a given month.

Given penile injections are prescribed by a medical professional, always defer to the advice given to you by your consultant as the number of injections and dosage can vary from person to person based on personal health needs.

As well as insuring that you don’t have too many injections within a specified time frame, it’s also important that you alternate between the left and right side of the penis when injecting.

If injecting regularly, this will further help to reduce tenderness, bruising and pain at the injection site.

What are the side effects of penile injections?

Despite having been medically approved in the United States since 1981, as with any medication whether injectable or in tablet form, there are always an associated list of potential adverse side effects – Alprostadil and TriMix are no different.

The most common type of side effect from a penile injection (a symptom experienced and reported in more than 37% of cases) is that of an ache that occurs between 5 to 20 minutes after initial injection. In most cases the ache is very dull and mild to moderate in nature.

The cause of this ache can be put down to a number of factors however the common thinking is that potassium that is present in the medication causes this added ache – in such cases where the ache is untenable, use of an alternative branded solution such as TriMix can then be used.

Beyond the aching pain that can occur you may also experience some small bruising in the area of the injection site with very rare occurrences of small lumps appearing when the injection is administered in the same location numerous times.

With that in mind it’s always best to alternate between the left and right side of the penis when taking the injection.

In rare cases a side effect called Priapism can occur – this is where the medication produces a prolonged erection – an erection that can be painful and sustained for more than 4 hours. In such instances medical attention and treatment should be sought as quickly as possible.

It is also worth noting that some people can experience an allergic reaction in the form of difficulty breathing, swelling of the face, tongue, lips, or throat, so if you start experiencing any of these symptoms, or become lightheaded, experience any pain lasting more than 4 hours or have any other unusual symptoms, always stop using the medication in question and contact your doctor as soon as feasibly possible.

Obviously if you have any of these symptoms, or are worried about how to properly or effectively inject your dosage of Alprostadil or TriMix, always talk to your medical practitioner.

It’s also very important that if you do exceed the recommended dosage, that you seek medical help and attention as quickly as possible.

So in summary…

There it is – pretty much everything you need to know when considering whether or not penile injections are “right” for you.

Are you considering penile injections? Have you done a penile injection before? If so how did it feel, and what were your results? Did it work? Let us know in the comments below and share your experience with our community.