Erectile Dysfunction

The inability to attain or maintain an erection long enough for sexual activity is called erectile dysfunction or impotence. 

As a quick review, erections are triggered in three different ways – through mental stimulation (psychogenic), physical stimulation (reflexogenic), and hormonal stimulation.  These forms of stimulation cause nitric oxide (NO) to be released into the blood vessels of the penis which cause the erectile tissue to fill and swell with blood causing the penis to become erect.  In the final stage of an erection, the penis becomes rigid enough for intercourse.  When the penis becomes fully erect, a chemical called cGMP helps maintain the erection.  cGMP is broken down by an enzyme called phosphodiesterase (PDE-5).  

Erections subside for two different reasons.  First, as stimulation subsides, cGMP is broken down by PDE-5 and the blood is released from the erectile tissues back into the body and the erection subsides.  Second, signals and chemicals from the nervous and endocrine systems cause the blood vessels that feed an erection to clamp down and stop supplying blood to the penis, thus causing an erection to go away.  Erections typically subside either because stimulation has decreased or because ejaculation has occurred.

Erectile dysfunction can occur for a variety of reasons ranging from disruption of one or more of the three stimulation pathways, anatomical problems with blood supply, penile pain, medications, or even just psychological reasons (including “stage fright” or “fear of not achieving and erection”). 

  • Psychogenic – For nearly 90% of men, the problem may be that the nervous system does not respond to mental or physical stimulation as well as it should.  This can either be due to “stage fright”, “mental block”, or simply the fear of not attaining or maintaining an erection can cause enough “disruption” in the central nervous system to cause impotence.  In addition, men who have been involved in pornography often become accustomed to abnormally high levels of mental stimulation, and normal sexual relationships can fail to trigger psychogenic responses (they become numb to normal levels of sexual excitement).  Yet other times, there can simply be problems with the nervous system itself.  In fact, some disorders of the nervous system can inhibit erectile function – like spinal cord injuries, lesions on the nerves, Parkinson’s Disease, Multiple Sclerosis, and other neurologic diseases. 


  • Reflexogenic (physical) – Physical stimulation is also important.  A decrease in physical stimulation can cause an erection to subside in most men, but it will bounce back upon further physical stimulation.  However, men that have had chronic sexual addictions, especially to prolonged or repeated masturbation can fail to respond to normal levels of physical stimulation involved in normal sexual relationships.  This can cause the penis to not become as rigid as it needs to be for intercourse, or the penis requires non-stop physical stimulation in order to stay erect. 


  • Hormonal – Problems with erections can occur if the tissues in the penis are not as healthy as they once were.  Failure to have nocturnal erections at night can cause the tissue in the penis to not get as much oxygen as it needs to be healthy.  In these cases, increasing testosterone levels can help men have more frequent and more rigid erections during sleep to help oxygenate and nourish these tissues.  In some cases, men who have pornography or sexual addictions become so reliant on intense psychological or physical stimulation that the penis fails to respond to testosterone during the sleeping hours and nocturnal erections can cease – thus leading to “less healthy” erectile tissue.


  • Physical health problems can cause problems with attaining or maintaining an erection.  Some men have problems with the vasculature (blood supply and blood pressure) that feeds the penis with blood.  Others who have pain in the penis can have “sexually stimulating messages” being overridden by “pain messages” to the spinal cord, thus causing an erection to go away.  This may be especially true in men that get painful erections either due to injuries, curvature of the erect penis, or prostate infections.  Erectile dysfunction is also more common in men who are overweight and in those who use alcohol and/or tobacco.  Finally, some men may fail to get an erection because medications are interfering with the signals from the nerves or negatively influencing the blood vessels that allow an erection to occur.  Some medications that affect the blood vessels or blood pressure can reduce blood flow to the penis.  While medications such as antidepressants or tramadol that increase serotonin (a neurotransmitter that is released right after ejaculation) can inhibit an erection (just like a man can’t get an erection right after he ejaculates).  

As stated earlier, there are two main types of erectile dysfunction or impotence.  The most common type is the failure of a man to maintain a rigid erection long enough for sexual activity.  The second is less common but involves the inability of a man to attain an erection at all (or at least an erection rigid enough for intercourse).

Problems maintaining an erection


As stated earlier, PDE-5 breaks down cGMP which allows an erection to continue.  However, in some men, cGMP can be broken down more quickly than it is produced, leading to the loss of an erection before intercourse can occur or the inability to have an erection stay rigid long enough for intercourse to begin.  As stated above, mental, physical, and/or hormonal issues may be at play.  For some men, the fear that they will not maintain their erection long enough is enough of a barrier in the nervous system to fulfill the prophecy of their own fears. 


The main medications used to treat men who have difficulties maintaining erections are the PDE-5 inhibitors like Viagra® (sildenafil), Levitra®/Staxyn® (vardenafil), Cialis® (tadalafil), and Stendra® (avalafil).  These medications inhibit PDE-5 thus preventing it from breaking down cGMP.  This allows an erection to be maintained for a longer period of time.  Although these medications work well, oftentimes simply the “thought” of taking something to help prevent ED, decreases the worry and stress, which actually helps a man maintain an erection.  In fact, in many studies, 40% of men who were given a placebo (inactive tablet) were able to maintain erections better even though they didn’t receive any drug – simply because their anxiety was reduced.  If a man has difficulties in this area, it’s always good for him to pay attention to whether or not he is having erections at night.  If he is having nocturnal erections, talk therapy or simply reassurance from his partner can improve erectile function significantly.  If erections during sleep are rare or absent, it’s a good idea for him to check with his healthcare provider to see if hormone replacement or PDE-5 therapy could be helpful.  It’s important to understand that PDE-5 inhibitors will not help a man get an erection, but they will help him maintain the erection longer.  That is why it is still important in these men to be able to attain or get an erection through stimulation (mental or physical) before the PDE-5 inhibitor drug actually begins to work. 


Most of these medications take 30 minutes before they get distributed from the pill that was swallowed to the tissues of the penis.  For this reason, they should be taken 30 minutes prior to sexual activity.  One exception to this rule is tadalfil.  Tadalafil stays in the bloodstream longer, and can keep working for up to 3 days so redosing it for intercourse that occurs within three days is not necessary.  Furthermore, some men are prescribed tadalafil in smaller doses each day so that they can be more spontaneous in sexual activity rather than having to plan 30 minutes ahead.  A downside to tadalafil is that the medication is always in the body and so the side effects may stick around longer as well.    Here are some of the side effects of PDE-5 inhibitors:

  • Low blood pressure – this can cause some men to become dizzy, especially if they stand up quickly.  In fact, one type of heart medication, nitroglycerin, can cause a serious interaction with PDE-5 inhibitors that can lead to a complete loss of blood pressure which may result in death.  This is perhaps one of the most deadly drug interactions.  Nitroglycerin is used in people that have chest pain.  If you have heart troubles, discuss this with your healthcare provider before starting a PDE-5 inhibitor.  In addition, some meds used to treat some prostate conditions (alpha blockers) can reduce blood pressure as well and some healthcare providers advice against taking both PDE-5 inhibitors and alpha blockers together.

  • Priapism – PDE-5 inhibitors can also cause an erection to not cease when it should.  This condition is called priapism

  • “Blue vision” –  PDE-6 is found in the eyes, and one of the PDE-5 inhibitors, sildenafil (Viagra®), also stimulates PDE-6.  This can cause a man to have a blue-tinged visual field (like he’s looking through blue tinted classes). 

If antidepressants medications are a causative factor, physicians may prescribe a short-term serotonin antagonist (blocker) like cyproheptadine to reverse the erectile dysfunction caused by the medication. 

One non-drug therapy that men may hear of if they can't maintain an erection is to use of penis rings.    There are many available penis rings on the market, most of which are for sex play.  However, ONLY those rings that are approved as medical devices and recommended by your healthcare provider should be used for erectile dysfunction.  Non-medical rings may cause penile strangulation, inhibit semen from being ejaculated thus causing internal damage to the urethra, and a host of other issues.  Penis rings are typically used in conjunction with erectile dysfunction penis pumps prescribed or recommended by a healthcare provider (see section under penis pumps below).  Penis rings are not recommended for erectile dysfunction unless recommended by an individual's healthcare provider.

Problems attaining an erection

There are multiple options to help reverse this type of erectile dysfunction.  First and foremost, “stage fright” or “fear of not getting an erection” are among the leading reasons why men cannot get an erection.  Fear and anxiety trigger the fight and flight response.  This response leads to norepinephrine being released into the bloodstream that help us run from danger, increase muscle strength to move a heavy object that has fallen on someone, etc.  However, as we’ve already discussed, norepinephrine is the chemical that helps keep the penis flaccid during the day.  So anxiety can stop an erection before it even has a chance to begin.  This type of ED can be treated by talk therapy and reassurance as well.

For men who simply cannot initiate an erection ever, there are drug and non-drug therapies to treat this type of ED.  The first is to administer prostaglandins.  Prostaglandins trigger the penile tissues to release nitric oxide (NO) to start the erection process.  This is why treatment for men who truly have the inability to attain an erection often requires prostaglandin treatment.  Unfortunately, prostaglandins do not work when taken orally and must be administered directly into the penis. 


There is only one prostaglandin medication available in the United States for erectile dysfunction – alprostadil.  Alprostadil can be administered into the penis either by injection or by urethral suppositories.  For men who do not respond to alprostadil therapy or don’t wish to give themselves injections or insert pellets down their penis, then a penis pump can be used to help him attain and maintain an erection.  More invasive therapies can also be an option for some men including surgery to correct blood flow issues or even penile implants.  To see medical illustrations on the following therapies, click HERE.  Details about each of these therapies is listed below:

  • Alprostadil injections (Caverject® and Edex®) are injected directly into the shaft of the penis (typically about mid-shaft on either the upper left or upper right side of the back of the penis (at about the 10 o’clock or 2 o’clock positions).  To see a medical illustration of how a penile injection is given click HERE.  Within a minute or so, the penis will start to become erect.  A man must be trained by a healthcare provider how to give himself these injections so he can avoid the many blood vessels found in the penis (alprostadil should not be injected into any blood vessel).  The main side effects of alprostadil injections are pain and bleeding at the injection site.  Priapism or failure to end an erection is also a side effect.  Sometimes, a compounded prescription called “Tri-Mix” is prescribed to men that contains alprostadil and a vasodilator like papaverine as well as another medication.  These other medications have not been approved for use in erectile dysfunction but some clinicians feel they provide benefit for their patients with erectile dysfunction.

  • Alprostadil urethral suppository (Muse®) is a small pellet of medication inserted into the urethra of the penis.  The pellet is located on a small applicator (it looks like a small toothpick) that is inserted into the urethra of the penis.  Once it is inserted about an inch down the urethra, a button on the top of the applicator is pressed to release the pellet and the applicator is withdrawn from the penis, leaving the pellet behind.  The man must then roll the penis between the palms of his hand to help the pellet dissolve and leach into the erectile tissues of the penis.  Again, an erection will begin to occur within a few minutes.  Side effects include the risk of scratching the urethra leading to some bleeding out of the tip of the penis or blood in the semen.  Priapism is also a risk.

  • Penis Pumps - Instructions for how to use a penis pump typically come with the pump.  There are multiple penis pumps available on the market, many of which are for sex play or “size enhancement”.  However, ONLY those pumps that are designed as medical devices that are recommended by your healthcare provider and approved by the FDA or some other nationally recognized medical board are suggested as others may  cause too much blood to rush into the erectile columns and potentially cause penile damage.  Always follow the direction or your healthcare provider.  However, for most pumps it comes with a cylinder attached to a vacuum tube and rubber penis rings.  A rubber ring is typically placed on the end of the cylinder, then the penis is placed in in the cylinder and the cylinder is pressed against the pubic bone to create a seal.  The vacuum is then turned on or the air is pumped out or it is hand pumped.  The vacuum pressure pulls blood into the penis causing it to become erect.[i]  In order to maintain the erection, the rubber ring[ii] is simply rolled off the cylinder onto the base of the penis once the penis is erect.  This ring will often restrict the dorsal vein and trap the blood in the penis to maintain the erection, but allow a grove in the bottom of the ring for the underside of the penis to allow semen to flow through the urethra (to see an example of a penis pump ring for erectile dysfunction, click HERE- note this is not an endorsement of this particular product, rather an illustration of what a medical type penis ring looks like). However, men must be careful using this method since the root of the penis is not erect.The penis will only be erect from the ring upwards causing the penis to not stand erect.Since the root of the penis is often not erect, the erection is not supported by the penile muscles and ligaments appropriately.This lack of rigidity along the entire penis can cause kinking of the erectile tissues below the ring and prevent lower penile rigidity often necessary for intercourse.Oftentimes a man may have to stabilize the lower portion of the penis with his hand during sex or engage in sexual activity gently.In addition, the ring should not be worn for more than a few minutes as it can cause penile strangulation.  As soon as ejaculation occurs, the ring needs to be removed from the base of the penis.It is not uncommon for some men to not notice any semen being ejaculated when using a penis pump.This can be caused by the penis ring restricting semen from exiting the penis.It’s not uncommon for men to have semen leak out of the penis when the ring is removed.However, ejaculation is a high pressure event and many men will notice some semen being ejaculated, so penile rings should NOT be used as a lazy form of birth control.  Below is an image of a generic pump, medical pumps come varying designs and may not look exactly the same.


Penile Implants/Prosthesis – For some men who have irreversible erectile dysfunction (tissue damage, spinal cord injuries, etc.), permanent implants can be inserted into the penis.  These implants contain reservoirs in the penis and a pump located outside of the penis (often in the scrotum) which can be pressed and the pump pushes saline into the reservoirs causing an “erection”.  So rather than blood causing the erection, saline causes the erection.  It can then be “deflated” after sexual activity.  Some older implants that are rarely used anymore consist of rods that keep the penis erect at all times. This can be uncomfortable (imagine walking around with an erection all the time) and sometimes difficult to hide beneath clothing since the penis is technically “always erect”. 

[i] (3/25/17)

[ii] (1/15/2020)

  • Surgery – Rarely is surgery recommended as it is fairly invasive.  Typically surgery involves reconstruction of the blood vessels that feed the penis.  It’s often not recommended because it doesn’t always work and can end up being very expensive.


“Partial” Erectile Dysfunction

Some men complain of having “partial ED”.  For some, the penis is only semi-rigid while in others the shaft of the penis can become erect but the glans remains soft (sometimes termed “soft glans syndrome”).  Yet in other men, they can achieve a rigid erection in some positions (standing for example) but not in others (lying down).  Most often, these types of ED can be attributed to a condition called venous leakage.

In venous leakage, blood is able to enter the penis, but the veins in the penis don’t fully clamp down allowing the penile structures to become rigid.  Instead, some of the blood escapes the erectile tissues keeping the penis from becoming fully rigid.  If this leakage affects all columns of erectile tissue then the penis is semi-rigid.  If the leakage only affects the corpus spongiosum, then the shaft of the penis can become rigid but the tip of the penis will remain somewhat soft thus making sexual intercourse difficult or even impossible.  As stated earlier, in some men, this leakage only occurs when he is in certain positions (lying versus standing) so changing sexual positions so that leakage doesn’t occur is often an easy first line treatment.[iii]

Venous leakage can be found in men with trauma injuries to the penis, Peyroine’s disease, or other disorders.  However, it may simply be due to how the blood vessels developed – in these cases, venous leakage has often been present since puberty.  Initial treatment may include many of the same medications for other types of ED like PDE-5 inhibitors or prostaglandins.  However, for some men, surgery to correct the leakage in the blood vessels may be necessary.  In some men who can achieve a rigid erection but lose it quickly or in certain positions, a medically approved penile ring may be placed over the base of the penis when it is rigid-erect to prevent loss of blood flow and allow for sexual activity (same principle and warnings apply as the rings used with penis pumps mentioned above). 

Another cause that doesn’t deal with venous leakage can occur in men who have had a penile implant.  “Soft glans syndrome” can occur when the implants increase rigidity in the shaft of the penis but lack of sexual response in the glans may leave the tip of the penis soft.  This can often lead to issues with inability to penetrate the vagina since the glans is not firm, bends, and becomes tender.


However, for some men this partial rigidity can occur due to other issues such as stage fright, anxiety, or other psychological issues.  It can also occur in men who engage in a high rate of sexual activity over a short period of time (such as excessive masturbation).  In these cases, psychological therapy can be a helpful treatment.

[i] (3/25/17)

[ii] (1/15/2020)

[iii] (3/20/17)

Images on this page from top to bottom include:

  1. Eillen/

  2. Ellepigrafica/