Your Body During Sex

Sex is one of the most primal needs of human beings. According to WebMD, there are 4 phases that happen during a sexual intercourse. Masters and Johnsons are two sex therapists who created the concept of a cycle that happens to the human body once aroused and during the course of a sexual activity. They call this the Sexual-Response Cycle. According to Sex Info Online, the sexual activity is not exclusive to penile-vaginal intercourse, as the same cycle is also undergoing during masturbation, manual stimulation of partner, oral sex, or fantasy.

As per, since it is a cycle, there is no real endpoint, and it the concept is only a very general framework of the sequence of physical and emotional phases that the body goes through in the course of any sexual activity. The cycle may recur or end and varies dependent on the individual and the events happening to the individuals. As provided by Sex Info Online, People who try to demystify their sexual experiences must put in mind that they should not consider it as a checklist, as doing so may result in the participants of the sexual act not enjoying the experience. They also provided that this simplistic 4-step method does not give justice to the varying motions, cues and responses that each individual, or each sexual encounter may consummate.

The Masters and Johnson’s 4-Phase Model is said to be applicable to both men and women, regardless of their sexual preferences, but the duration of each stage may differ. The difference in the male and female model will explain the varying timings and sensations in a hetero relationship. But even in cases of man-on-man or woman-on-woman encounters, the variation still exists based on the individual though they are generally predictable. However, through communication, both parties can achieve a satisfying sexual experience.






The first phase in the Sexual-Response Cycle, is Excitement. The duration of this stage is highly dependent per person and situation, it is said to last from a few minutes to many hours, according to WebMD. Signs that the body is in this phase for both sexes include: increased muscle tension, heart rate, blood pressure and breathing as well as harden or erect nipples. For women, vasocongestion results in the swelling of the clitoris, labia minora and vagina; vaginal lubrication also happens and breasts become fuller. For men, the penis erects, the testes swells and the scrotum tightens.

The second phase is called the Plateau, and as its name suggests, is the period of sexual pleasure anticipating the climax. Indications that the body has reached this stage is the intensification of the sensations felt in phase 1: breathing, heart rate, blood pressure accelerates even more; muscle tension increases in the thighs and buttocks; spasms are felt in the feet, face and hands. Both men and women also start to vocalize involuntarily in this phase. For men, the testes are drawn up to the scrotum and the penis becomes fully erect. While women experience ultra-sensitivity in the clitoris which retracts under the clitoral hood to avoid direct stimulation or contact; and the vaginal walls continue to contract due to increased blood flow and the color turns the inner labia to a darker shade of bright red to purple. Finally, the Bartholin gland also produces further lubrication.

The third and probably the most controversial stage in the cycle is the Climax or the Orgasm. It has the shortest duration of the four phases and only lasts for a few seconds. Here, breathing, blood pressure, pulse rate further increases; flushes or rashes in the skin appear throughout the body while muscle tension is at its peak resulting in involuntary muscle contraction, muscle spasms and a sudden release is felt. Women experience vaginal and uterine rhythmic contractions while men experience the same contractions at the base of the penis and seminal fluid collects in the urethral bulb, then semen is ejaculated from the penis.

The final stage is the Resolution phase, which happens immediately after the Orgasm. This stage, however, varies deeply between the sexes as women have the ability to experience multiple orgasms with small time differences in between, whereas men have a longer Refractory Period where they are unable to become aroused with stimulation for a certain amount of time and orgasm again, dependent on their age among other things; though women are also reported to having experienced the same.

Your Brain On Sex

Now that we have a clearer understanding of our bodies during sex, it is time to understand sex on the “thinking” perspective, though it must be known that brain functions can turn out to be irrational and unthinking. Different from the bodily functions, the “sex” happens long before the first sexual contact for the brain.

In an article at, for the brain, it starts with attraction which is an increased activity in the amygdala. If the involved parties kiss, testosterone is passed between the two which is the hormone responsible for aggression and is linked to sex.

From here, whether the attraction will lead to a sexual contact is determined. Medical Daily states that during sex, the brain is the pleasure center and dictates which acts are enjoyable and are not. A familiar euphoria is felt during sex which is neurochemicals flooding the brain that create feelings of attachment, and even love.

Some of the natural chemicals that go center stage during intercourse are the following, as enumerated by Feed the Right Wolf, a website for recovering porn addicts.

  • Testosterone – This is the hormone produced by the testicles, but women also have small quantities of this in their system. This chemical is the one responsible for sexual desire, and thus is the most primal of the set of chemicals released during sexual activity.
  • Estrogen – This chemical ignites female libido, and peaks during ovulation. During this time, the female may see the male they are with as most attractive.
  • Dopamine – Similar to Testosterone, Dopamine is related to increasing sexual desire, however, this chemical digs a little deeper and doesn’t just determine desire but also craving, attachment and addiction, according to an article at Entelechy. It is called the pleasure chemical and described in an article by Bryan A. Sands as that which rewards the brain and gives a feeling of goodness and euphoria.
  • Norepinephrine  Related to Dopamine, Norepinephrine generates exhilaration and gives the body adrenaline, and is further related to memory. Whatever details and stimulus experienced during the presence of Norepinephrine will be etched into memory.
  • Vasopressin – Also known as the monogamy molecule, this is important in creating a desire for to stay with one mate and growing protective of the partner, which also drives jealousy and loyalty.
  • Oxytocin – On the other hand, women are affected more by oxytocin, or the love hormone. This chemical is released through physical contact of hugging, touching and orgasm, and is said to be responsible for creating a bond between two individuals.
  • Serotonin – The feel good chemical, serotonin, also found in anti-depressants, creates stimuli associations that make individuals feel satisfied and less depressive.

Love, Sex and Other Drugs

As discussed previously, sex releases chemicals, and in this line, between the irrational attachment, impulsive craving, among others, we can say that somehow, despite all the wonderful, fantastic things it is said to be, SEX IS A DRUG.

In a listicle published by, through a research conducted at Rutgers University in Newark, NJ, that involved MRI scans of people masturbating and having intercourse, a few findings come to light. These results were also echoed by the Daily Mail.

Sex is likened to drugs as the chemicals released by the brain shows a similar activity in certain brain regions with the brain activity of someone on cocaine. Sex is also said to have the same effect as an antidepressant, though at the other end of spectrum, it can also be a downer in a state called postcoital dysphoria. Sex was found to lessen if not completely relieve pain symptoms. It also has the tendency to wipe the memory clean, though temporarily, in a condition called global transient amnesia; and at the opposite pole, activate the hippocampus to boost one’s memory. For those who experience manic or stressful episodes, sex is also said to have a calming and tranquilizing effect.

Chemical Reaction

Given the amount of chemical reactions that happen within the body and the brain during sex, participants in any sexual activity are bound to find themselves feeling a plethora of sensations and emotions brought about by participating in sexual activity. It is never really just sex with the amount of chemical reactions the body undergoes in an hour’s worth of body bumping, sweating, moaning and breathing heavily.

This can be easily explained if life was black and white and sexual intercourse happens to two consenting parties who are mutually looking forward to a healthy, meaningful relationship. Two individuals get attracted to each other, and in the course of the attraction chemicals kick in, stimulating their senses, they have sex, enjoy it, repeat it, and in the process find themselves bonded and attached to each other, decide on exclusivity because they mutually feel satisfied about each other and protective of the relationship. They get married, get pregnant, have a baby, then it’s a happily ever after.

More often than not, it’s not quite as simple in the real life. Humans are complex beings, not driven by sex, or a need to be with someone alone, and as such, the relationships they forge can be complicated too. So how does sex factor out if it’s not the traditional love story? Just as sex causes all the good feels, sex may also be blamed for all the heartache that happens when a love story has gone awry or the confusion felt when people are not quite sure how to traverse what was initially envisioned as something to be done for fun and not commitment.

Casual Sex

A set up that is growing popularity according to the New Yorker, casual sex is prevalent with 80% of college students reporting to have engaged in sexual acts outside a committed relationship. A behavior driven by the changes in the societal norms, with men and women not as keen to be tied in a relationship and are more driven with other goals like careers, passions and travel that may be hindered by being in a committed relationship.

As long as the participants are aware of what to expect in such an exchange and keeping themselves protected, casual sex poses no real threat to the parties involved. A one-off experience will remain as it is if the parties involved are psychologically and emotionally ready to partake in a non-strings attached encounter, only meant to satisfy carnal desire and pleasures.

To ensure the success of casual sex, GQ also created a set of rules to maneuver in this environment which involves setting their emotional expectations and controlling their portions, these two are important points in keeping casual sex, casual.

As provided by the many effects that an individual may experience due to several chemical components happening during a sexual intercourse, the odds of the chemicals affecting one’s brain resulting in confusing cues are inevitable and can cause one to feel attached, feel a craving, and bonded. Even kissing is said to affect expectations as Daily Mail stated that kissing also releases pleasure hormones long before actual sex – maybe also the reason why urban legend has it that kissing must be avoided in casual sex scenarios. Prolonged exposure to these chemicals with one individual is likely to skew your expectations and emotions, and what you intended to be casual may suddenly come with so many strings attached.

Letting Go

Daily Mail also wrote that oxytocin is also found to be the chemical responsible for letting down our defenses and make humans trust another person. Women produce more oxytocin than men, which deem them more likely to be victims of the chemical and fall in love.

It is this dynamic that makes separations and heartbreaks difficult to manage. When the chemicals have already circulated and have affected your psyche during sex with someone, in the duration of the relationship, one will start feeling a longing due to growing attached and creating memories, feeling incomplete as the pair have bonded, and since the other person’s presence is associated with feeling good, their loss customarily will make you feel the opposite of good. confirmed this, saying that when people love, the other person is integrated into their lives that when the other person is gone, people feel lost.

Stockholm Syndrome and Abusive Relationships

The same chemicals may be blamed for some cases of Stockholm Syndrome. This is a psychological phenomenon introduced in the 70s where hostages express sympathy / affection for their captors. Though this syndrome is not considered to be exclusively of a sexual nature, the power dynamics in the setup may be compared to abusive relationships, where the abused finds it difficult to leave the relationship despite obvious reasons. The abused exhibits sympathy and attachment created by sexually-induced chemical reactions that clouds their senses causing irrationality.