The science of orgasm: Why does it exist at all?

Why the male orgasm exists seems clear: the ejaculate is needed for reproduction. On the contrary, the female orgasm still offers much room for research.

A firework of emotions: Liberation, relaxation, relief—there is hardly any other experience that we perceive as intensely as the orgasm. And yet it lasts less than a minute on average. But what exactly happens during the climax? How do male and female orgasms differ? And why does it exist at all? These are just some of the questions that arise.

No matter whether during sex with a man, a woman, or during masturbation, everyone, ideally, has experienced an orgasm at some point. Both in society and in science, however, many mysteries still surround the climax. Orgasm is often experienced as a completely exceptional state of the body; the mind seems to be completely switched off for the moment. But this is not the case at all.

What happens in the body during orgasm?

Although orgasm usually lasts only a few seconds, a lot happens during it. Many organs play together, with the sexual organs becoming particularly active. So what exactly happens in the body during the orgasm? The course of an orgasm can be described by a so-called arousal cycle. This includes four stages.

The tension increases

It begins with the arousal phase, which can be triggered by touch, imagination, or the subconscious alone. During this phase, the genitals swell. In women, this affects the clitoris, vulval lips, vaginal walls, and nipples. In addition, a vaginal secretion is discharged, moistening the vulva. In men, on the other hand, the blood vessels in the erectile tissue of the penis dilate, allowing more blood to flow into the member. Because the veins are compressed in the process, the blood can no longer flow out, and the penis becomes erect.

No way back

This is followed by the plateau phase, in which the high feeling of pleasure continues. Some people also experience the high arousal as wave-like. Just before the next phase, the climax, occurs, men experience what is called “ejaculatory inevitability.” This marks the phase when sperm have already been pumped through the sperm duct into the prostate, where they mix with seminal fluid and are passed into the urethra. This period, however, covers only a few seconds.

The great spectacle

When men climax, the sperm is then shot out of the penis at a speed of about 17 kilometers per hour by rhythmic muscle contractions. At the same time, the urethra’s access to the bladder is closed. In men, the climax lasts about twelve seconds on average. In women, on the other hand, climax can last an average of 13 to 51 seconds. This involves the contraction and widening of the outer part of the vagina, the uterus, and the surrounding muscles in a rhythm of about 0.8 seconds.

Some women also experience a type of ejaculation. This is often referred to as “squirting.” Its existence has been scientifically confirmed for several years. Likewise, it became clear relatively quickly that the paraurethral glands, also called Skene glands, are associated with it. These are located in the glandular tissue surrounding the urethra and are comparable to the male prostate.

However, it is not yet certain whether all women possess Skene’s glands and thus whether every woman is physically capable of ejaculating. The composition of the secretion is equally uncertain. A study published in April 2022 shows that different fluids are secreted, and therefore a distinction must be made between “female ejaculation” and “squirting.” According to this study, female ejaculation is a viscous fluid that is secreted from the Skene glands and contains a high concentration of prostate-specific antigen, a protein substance.

According to the researchers, the thin, colorless fluid excreted during squirting, on the other hand, comes from the urinary bladder and is more similar to urine. However, the two processes could occur simultaneously. Other sources state that squirting secretion consists of urea, uric acid, and creatinine, among other substances, and is secreted by the Skene glands. Thus, research on the fluids that can be expelled during female orgasms is still very young and controversial, which is why the phenomenon cannot yet be fully explained.

Some effects of climax are experienced by women as well as men. Breathing rate and pulse are significantly increased in all, vessels become more perfused with blood, and more oxygen reaches the muscles and organs.

Second round?

Immediately following the climax is the refractory phase. During this phase, the feeling of pleasure decreases rapidly until it finally disappears completely. At least this is the case with men, because with women, further plateau phases can also follow. Therefore, unlike men, they can experience several orgasms in a row.

From the genitals to the brain – and back

Actually, it sounds quite contrary: Just when we let go the most, and feel virtually free of all problems, our brain works at full speed. This is because all physical and psychological changes during orgasm are ultimately triggered by the brain. While the orgasm is outwardly different for women and men, the perception and the basic processes in the brain are very similar for both sexes. The hypothalamus is the linchpin of this process. Its task is the control of hormones, whereby it has an influence on our entire body.

The way there

However, before the big climax happens, a few other things happen. First, stimulation of the sex organs in the brain activates the genital sensory cortex, an area of our cerebral cortex that sits roughly in the middle of our parietal region and is responsible for processing sensory input. Stimulation of different sexual organs activates different regions of the cortex, which is why stimulation of several erogenous zones at the same time can also lead to a more intense orgasm. If a triggered stimulus is intense enough, it is transmitted to the diencephalon, where it reaches the hypothalamus. This serves as a kind of mediator between the nervous and hormonal systems.

Hormone surge during the peak

When climax occurs, the hypothalamus suddenly releases large amounts of hormones. The so-called “cuddle hormone,” oxytocin, is what mainly causes the intoxicatingly pleasant feeling of an orgasm, as researchers found out in a study. Men were given an oxytocin-inhibiting agent before sex or masturbation. As a result, the subjects still orgasmed, but did not feel satisfied or happy in any way. In addition, the hormone contributes to increased heart rate and short-term high blood pressure, dilates the pupils, and still promotes bonding and trust with the other person, especially after orgasm.

Dopamine is also called the “happy hormone” for a reason. It also has an arousing effect during orgasm and causes a kind of intoxication of feelings of happiness. By additionally releasing the hormone serotonin as well, the body’s pain suppression system is activated. Thus, the sensitivity to pain decreases significantly during orgasm.

And conclusion

After sex, serotonin also contributes to the feeling of satisfaction and relaxation. To end the intoxicating effect of dopamine again, the pituitary gland also secretes the hormone prolactin. This is responsible for breast growth and milk production during pregnancy and breastfeeding. At the same time, it also has a calming effect. After orgasm, prolactin inhibits the effect of the happiness hormone and supports the feeling of satisfaction. The activity of the hypothalamus decreases again.

Why women orgasm less often?

While the hormonal basis of orgasm in women and men is very similar, there are some differences. There is still a lot of ignorance about the female body, both in science and in society. Time and again, women report only faking an orgasm during sex because they so rarely or never experience orgasm through heterosexual intercourse.

A U.S. study involving just over 50,000 people also found that about 95 percent of men and only 65 percent of women orgasm through heterosexual intercourse. This means that almost one-third of women do not usually experience a climax during sex with men. What circumstances make it so difficult for many women to reach it?

Freudian influence

One reason is years of misconceptions about female sex organs. For example, it was long assumed that a distinction could be made between clitoral and vaginal orgasms. According to this, an orgasm could be achieved either by stimulation of the clitoris, or penetration of the vagina. The founder of this theory was Sigmund Freud. The neurologist and creator of psychoanalysis was one of the first to study orgasm more intensively at the beginning of the 20th century.

However, Freud judged the vaginal orgasm to be the “only real” one, as a result of which the clitoris also lost its social significance in the long term. The theory of inferior clitoral orgasm was based on the assumption that the clitoris was limited to the visible, pearly part called the clitoral acorn. Today, however, it is known that this is not the case. In fact, the inner part of the clitoris divides into two legs and surrounds the urethra and vagina in a horseshoe shape. Thus, the clitoris is also indirectly aroused during “vaginal orgasm.”

All roads lead to the clitoris

So actually, the opposite of Freud’s theory is more true: The clitoris plays a crucial role in female orgasm – regardless of how it is brought about. Anatomically, the clitoral glans are very similar to the male glans. However, because its nerve endings are distributed over a much smaller area, it is approximately 50 times more sensitive. The vagina is much less sensitive compared to the clitoral glans, which is why many women cannot reach orgasm through purely penetrative sex.

Furthermore, the fact that women climax so rarely during sex compared to men is also due to the fact that the female orgasm is generally more complex. There are many different erogenous zones and therefore many different preferences. Psychological pressure can also negatively influence the ability to orgasm. Therefore, trust, communication, and getting to know the female body are often essential to achieving orgasm as a woman.

Orgasms in the animal kingdom

“Multiply like rabbits.” This saying does not come from nowhere. Rabbits have a lot of sex. And they are not alone in this in the animal kingdom. Cats, mice, dolphins, and bonobos—they all like to reproduce. But why is that? Do they also experience orgasm?

In fact, it’s unclear whether all animals can have an orgasm during sexual intercourse. However, for some, there is evidence that they do experience a corresponding climax. This is the case for the majority of mammalian species. In other classes, such as birds, fish, and reptiles, there is little research on this.

Pseudo penis

One exception is the buffalo weaver (Bubalornis niger), native to East Africa. Researchers at the University of Sheffield have found that the males of this bird species have a penis that serves only for sexual stimulation and not for semen delivery. Orgasm is expressed in buffalo weavers by trembling and glazed eyes.

Joyful flippers

More findings are available on various mammals. These, too, are not always concerned only with reproduction. Just like humans, dolphins also have sex for pleasure. Researchers have repeatedly observed dolphins rubbing each other’s clitorises with their snouts, flukes, pectoral fins, or leeches. These sexual interactions could not only be observed between heterosexual couples, but especially increasingly between same-sex dolphins.

The reason for this behavior is most likely the large clitoris of female dolphins. This is located at the front of the vagina, which favors stimulation. The female dolphin’s clitoris also has a lot of stimulus-sensitive, excitable tissue because the erectile tissue has numerous nerve endings. Thus, the dolphin clitoris closely resembles the human clitoris.

Sex for social life

Bonobos also have sex without the goal of procreation. Rather, these great apes promote social interaction and resolve conflicts through sexual intercourse. This is especially true of same-sex relationships between female bonobos. The chimpanzee species even has more homosexual sex overall than heterosexual sex suitable for reproduction.

Researchers at the University of Leipzig found that female bonobos have higher levels of oxytocin in their urine after sex with another female than after sex with a male. Among other things, this could be a physiological basis for the fact that female bonobos also show a higher motivation to cooperate. This, in turn, has the advantage for them that it often also helps them achieve a higher rank in their community.

Induced ovulation

In some mammals, including rabbits and cats, orgasm is not only important for the social aspect, but it is even necessary for reproduction that both sexes climax. Clues to this are provided by the ovulatory cycle. In human women, ovulation is normally triggered about every four weeks, regardless of the frequency of sexual intercourse. However, this is not the case in all mammals: In some, ovulation occurs only after they have had an orgasm.

Mihaela Pavlicev of Cincinnati Children’s Hospital Medical Center and Günter Wagner of Yale University studied this connection between orgasm and ovulation in rabbits. They administered fluoxetine to female rabbits for two weeks. Fluoxetine is an antidepressant that inhibits orgasm in humans.

The results showed that after female rabbits treated in this way were placed with a male rabbit, the number of ovulations after mating fell by 30 percent. To rule out the possibility that the drug had a direct effect on ovulation in the rabbits, the females were also injected with the sex hormone human chorionic gonadotropin. This triggered ovulation despite fluoxetine, while orgasm remained prevented by the antidepressant.

This suggests that ovulation in rabbits is actually first induced by orgasm. The egg is stimulated to release from the ovaries by the hormones released during orgasm; fertilization can now take place.

The decisive stimulus for orgasm is also provided by the clitoris in female rabbits. Because it is located inside the vagina in rabbits, it is directly stimulated by penetration. However, whether rodents perceive orgasm in a similar way to humans is still unclear. However, there are some orgasm symptoms that are very similar in rabbits and humans, such as the sensation of warmth, increased lubrication, and involuntary muscle contractions in the vagina.

The biological origin of the female orgasm

The functions of orgasm in the animal world may offer possible solutions to one of the greatest mysteries of sexuality: the female orgasm. Why the male orgasm exists seems clear: the ejaculate is needed for reproduction. The orgasm and the associated ejaculation therefore serve to bring the sperm into the female genital tract. There, fertilization of the egg can then take place.

The female orgasm, on the other hand, does not play such a direct role in reproduction—at least not such an obvious one. Fertilization is also possible without the woman experiencing pleasure or orgasm during sex. So why does it exist? Over time, a number of theories have been advanced about its origin and biological meaning.

Like rabbits

One possibility: the origin of the female orgasm, regardless of its function today, could have its roots in the past. Mihaela Pavlicev of Cincinnati Children’s Hospital Medical Center and Günter Wagner of Yale University have theorized that the female orgasm was originally as relevant to reproduction as the male orgasm. According to this theory, female ovulation was also originally induced by female orgasm, as in some other mammals.

The theory is based on the very mammals and rodents in which this is still the case today: rabbits, for example. According to Pavlicev, orgasm itself, as a reflexive response to sexual stimulation, is the same in rabbits and humans. Only the hormone that causes ovulation is not secreted in human orgasm today. However, the increased release of prolactin and oxytocin during female orgasm could also be a clue to the connection. Because in many mammals, such as mice, these hormones also influence the cycle.

According to this theory, the independent ovulation cycle of humans and many other mammals, in which ovulation occurs at regular intervals regardless of sexual activity, would only have developed over time.

One possible reason that the independent cycle has prevailed evolutionarily is that the clitoris in humans and the corresponding female mammals are relatively far away from the vagina. Therefore, it is less stimulated during pure penetration, which reduces the likelihood of having an orgasm. Therefore, it may be that ovulation had to become independent of clitoral stimulation.

This theory of orgasm as a “remnant” of a previously necessary stimulation experience is now one of the most current and widely accepted. However, the researchers themselves note that more research is needed for clear confirmation. For example, it is also still unclear to what extent animal studies are actually applicable to humans. Similarly, causality in the clitoral position is not yet clear.

Evolutionary biology byproduct?

Another evolutionary biological theory is based on the anatomical similarity of the clitoris and the penis. Like the penis, the clitoris can fill with blood and swell to twice its size during sexual arousal. Both organs are also densely packed with sensitive sensory cells that send arousal stimuli to the brain.

The similarities are particularly striking in the early developmental stages of embryos, because the sex organs are formed from anatomically identical tissue. Therefore, they have a similar sensory apparatus and consist of similar neuronal structures. Thus, it stands to reason that the response to stimuli also traces back to these common roots. In this case, the female orgasm would be a kind of developmental biological byproduct of the male orgasm.

The present function the orgasm

Other explanatory models seek answers to the puzzle of the female orgasm more in potential present-day functions of climax. For example, some suggest that the muscle contractions of the vagina and uterus triggered by orgasm facilitate the sperm’s journey to the egg, increasing the chance of fertilization. However, this theory also still lacks evidence.

In addition, the hormone release accompanying orgasm may have an important psychological function. For example, dopamine and oxytocin provide a strong feeling of reward and happiness, respectively. The positive emotions could make the person want to have sex again, which would increase reproductive success. The cuddling hormone oxytocin additionally strengthens the bond with the other person involved. Consequently, the hormones would also be beneficial for the preservation of the species.

What is clear is that both the origin and the function of the female orgasm are still scientific mysteries. However, this does not mean that no attention should be paid to it. On the contrary, the female orgasm still offers much room for further research.

By Bertie Atkinson

Bertie Atkinson is a history writer at Malevus. He writes about diverse subjects in history, from ancient civilizations to world wars. In his free time, he enjoys reading, watching Netflix, and playing chess.