Erectile dysfunction is a common symptom of low testosterone, so if your erections have been less than robust lately, it’s reasonable to wonder if low T is the cause.
It’s possible, but unlikely.
Testosterone boosts libido, which triggers your erections, but according to the National Institutes of Health, only one in three men with ED also have low T (1). That means for the majority of men, there’s something else behind their flagging erections.
We asked urologist Wagner Baptiste, M.D., just how much testosterone plays a role in ED, what other conditions drive erectile dysfunction—and what to do about it, regardless of the cause.
How Does Low Testosterone Cause ED?
There’s no direct pathway for low testosterone to cause erectile dysfunction, says Baptiste. However, “symptoms of low testosterone, including a decline in libido, can impact your erections,” he says.
Here’s why: When your sex drive is low, it’s harder to get aroused. And when your arousal is sputtering instead of roaring, your body releases less nitric oxide, the molecule that relaxes muscles that allows blood to flow to your penis.
If you’re testosterone deficient, you’re also more prone to conditions that increase your risk for ED, including heart disease, type 2 diabetes, obesity, and anxiety and depression, Baptiste says.
Can high testosterone cause ED?
Yes, and it involves a hormone called estradiol. High T levels are caused by anabolic steroid abuse and sometimes testosterone replacement therapy (TRT), which is why treatment should be monitored by your doctor, Baptiste says.
Via an enzyme called 5 alpha-reductase your body converts testosterone into dihydrotestosterone (DHT), the most potent form of T. In the process, your body also produces estradiol through aromatization of testosterone, he says.
If you have too much testosterone, you’ll produce excess DHT and extra estradiol which is a form of estrogen, a hormone which helps regulate your libido and erections. The right balance is key; too much estrogen can squash your sex drive and cause ED, Baptiste says.
If a blood test indicates that your estradiol levels are too high, your doctor may prescribe an estrogen-blocking medication called anastrozole to regulate how much estrogen you produce.
KNOW YOUR T
Common Causes of Erectile Dysfunction
There are myriad causes of ED, but Baptiste offers a few main culprits.
The link between heart disease and ED is strong and direct.
“Men who have heart problems have issues with high lipids, high cholesterol, and atherosclerosis,” Baptiste says. “When a heart condition manifests as ED, it’s these other comorbidities that can lower your testosterone levels and make your ED worse.”
But the main effect is that heart disease blocks blood from flowing to your penis.
Heart disease is caused by plaque build-up in your arteries. The more plaque builds up, the more rigid your arteries become, making it hard for blood to flow through them to all areas of your body, including your penis, Baptiste says.
ED is sometimes the first red flag for heart disease, which is why it’s worth talking to your doctor if your erections start to wilt. The arteries in your heart and your penis are similar in size so plaque builds up at a similar rate. But your penis’ arteries are slightly smaller so plaque can build up earlier than in your heart (1).
Around 42 to 55 percent of men with diabetes have erectile dysfunction, Baptiste says.
“Diabetes directly attacks the nerves that are necessary for your erections,” he says. These nerves are responsible for sexual stimulation and you may lose sensation in your penis. This can make arousal and getting hard more difficult.
The condition also causes the inner lining of your blood vessels to lose function, affecting blood flow.
And because diabetes puts you at risk for low T, you could also end up with a lagging libido, which only makes ED worse.
Weight gain is a symptom of low testosterone. But in the absence of low T, obesity independently increases your risk for conditions including heart disease, high blood pressure, and diabetes, Baptiste says.
As a result of these underlying conditions, being obese or overweight leads to blood vessel damage which can torpedo your erections.
Anxiety and depression
The cause of erectile dysfunction isn’t always physical. About 20 percent of erectile dysfunction are rooted in psychological factors like stress, anxiety, and depression.
To understand how your big head gets in the way of your little one, you need to understand the role your central nervous system plays in erections.
When you’re aroused, your parasympathetic nervous system (PSNS) releases nitric oxide to help you get an erection. After you climax, your sympathetic nervous system (SNS) kicks in, constricting the arteries in your penis to force blood out.
If your SNS is constantly stimulated by stress or anxiety, it releases anti-erectogenic chemicals which override the ability of your PSNS to produce an erection, Baptiste says.
Depression also creates an imbalance of brain chemicals, including those that regulate sex drive and trigger blood flow to your penis when you’re aroused.
HELP YOUR ED
What is the Fastest Way to Cure ED?
Start with lifestyle changes. Cut back (or stop) smoking and drinking, and manage underlying conditions including diabetes, heart disease, and high blood pressure. Baptiste also recommends adopting these habits:
Your goal: 160 minutes of moderate to intense aerobic exercise a week. A review published in Sexual Medicine found that hitting this target for six months decreased ED caused by obesity, hypertension, metabolic syndrome, and cardiovascular disease (2).
Bonus: A 2022 review found exercise not only improved erectile dysfunction, but also decreased your overall risk for heart problems (3).
Clean up your diet
Plant-based diets rich in green leafy vegetables promote nitric oxide production, Jim Staheli, D.O., previously wrote for The Edge. Limit fats, sugar, and sodium; any amount of these contributes to inflammation which can lead to diseases that cause ED.
Chill out and calm your mind via breathing exercises, yoga, or meditation. Clocking enough sleep—seven to eight hours per night, can also dial down stress and anxiety.
If lifestyle changes don’t help resolve your erection issues, book an appointment with your doctor (here’s exactly what to say at the appointment). He or she may prescribe PDE5 inhibitors—like Viagra and Cialis—which are frontline soldiers for treating ED.
Testosterone Replacement Therapy and ED
If a blood test shows that your testosterone levels are below where they should be for your age, TRT can boost your sex drive and improve insulin resistance, both of which impact your erection quality, Baptiste says.
“TRT can also help PDE5 inhibitors work more efficiently,” he says.
The Bottom Line
Symptoms of low T, including poor sex drive, can impact the quality of your erections but only one in three men with low T experience ED. More serious conditions like heart disease and diabetes are more likely to cause ED. Cleaning up your lifestyle with more exercise, less stress, and a better diet can improve ED symptoms and help treat these underlying conditions.