Sexual Health > Penis and Testicle Health

Can You Be Allergic to Semen? Yes, Even Your Own

A pair of conditions can cause unpleasant symptoms when you least expect—or want—them.

man holds tissue to his red nose with a halo of sperm on blue background

Illustration by Brandon Cornwell

It's a fairly common joke that men tend to fall asleep after sex. But what if your post-climax experience feels more like an awful hangover, complete with a pounding headache and brain fog? Could it be that you're allergic to semen?

Postorgasmic illness syndrome (POIS), sometimes called postorgasmic sick syndrome, is a rare condition that causes flu-like symptoms within hours or minutes of ejaculation. It can happen with a partner, after masturbation or from a wet dream. Essentially, yes, it's like an allergic reaction to your semen.

What is postorgasmic illness syndrome?

First, know that postorgasmic illness syndrome is rare. It's estimated that fewer than 1,000 men in the United States have it, according to the Genetic and Rare Diseases Information Center (GARD).

As is the case with many sex-related conditions, though, there are probably patients who experience symptoms without ever consulting a doctor for a diagnosis.

POIS occurs when a patient experiences an allergic reaction to their own semen, said William Temple, M.D., a pathology specialist and medical director at Innovative Health Diagnostics in Santa Ana, California.

Postorgasmic illness syndrome (POIS) is a rare condition that causes flu-like symptoms within hours or minutes of ejaculation.

This might sound like a classic autoimmune disorder in which the body's immune system mistakes its own cells as foreign invaders and attacks, but the exact cause of POIS is still unknown, so the condition remains undefined.

Some experts call it an autoimmune disorder, while others call it an allergy disorder, according to GARD. Temple calls it an "atypical allergic reaction."

"The most accepted theory posits that a man with POIS may have an allergic reaction to his own semen, leading to an overactive immune response," he said. "The immune system, in this case, misinterprets the semen as a foreign invader and reacts accordingly."

What is human seminal plasma hypersensitivity?

Anyone can be allergic to semen.

Human seminal plasma (HSP) hypersensitivity is a rare allergy in women. It affects up to 40,000 women in the U.S., according to a 2011 review. This allergy to semen can cause both localized and systemic allergic reactions, said Abbas Kanani, M.R.Pharm.S., the superintendent pharmacist at Chemist Click online pharmacy in the United Kingdom.

POIS, on the other hand, affects only men.

"It is similar to human seminal plasma (HSP) hypersensitivity," Temple said. "In the case of POIS, the individual has an allergic response to his own semen."

What are the symptoms of an allergic reaction to semen?

"A localized reaction might look like skin becoming irritated or red when it comes in contact with semen," Kanani said. "Systemic reactions, on the other hand, can be more difficult to trace to ejaculate. Symptoms might include nausea or vomiting after coming into contact with semen."

With POIS, the following symptoms often develop within 30 minutes of ejaculation, according to Temple:

Fever
Fatigue
Body aches
Eye discomfort
Cognitive difficulties
Mood disturbances

What are the treatment options for semen allergies?

Not knowing what causes POIS can make it difficult to fix. However, there are potential treatments.

First, there is hyposensitization, also called desensitization therapy and immunotherapy. This involves gradual exposure to the allergen over time, potentially allowing the body to build a tolerance.

"The aim is to dampen the immune response," Kanani said, explaining that the immune system has a memory and can be gradually desensitized to what it considers harmful.

Men with POIS have also been treated with antihistamines (helpful for localized reactions on the skin, Kanani said), selective serotonin reuptake inhibitors (SSRIs) and benzodiazepines, according to a 2018 article in the Journal of Rare Diseases Research and Treatment.

In some cases, Temple said, regular ejaculation can be a potential treatment.

What do semen allergies mean for fertility?

If you're hoping to father a child, there's good news: POIS does not cause infertility. Neither the quality nor quantity of your sperm should be affected, Temple said.

However, conception gets tricky when one or both partners are allergic to semen. If you get a rash or feel sick whenever you ejaculate, you might consciously or unconsciously start avoiding sex.

"The discomfort and illness associated with ejaculation can understandably lead to a decrease in sexual activity, which could indirectly affect fertility," Temple said.

If POIS is interfering with your plans to have a child, you still have options.

Intrauterine insemination (IUI), in which sperm is inserted directly into the womb, is an option, Kanani said. In vitro fertilization (IVF) could work. Still, these methods of conceiving are costly and not always successful. They also don't resolve the problem of avoiding intimacy for mere pleasure.

The bottom line: Postorgasmic illness syndrome is a rare but very real impediment to your sex life. If you suspect you have it, talk with a healthcare provider.