Hormonal birth control can shift some aspects of attraction, particularly how you respond to a partner’s natural scent. The effect is real but narrower than internet headlines suggest. Most of the solid evidence centers on smell-based preferences and relationship satisfaction rather than sweeping changes in your “type.”
How the Pill Changes Scent Preferences
Your immune system has a set of genes that influence your natural body odor. These genes, part of a system called the major histocompatibility complex (MHC), vary widely from person to person. Women who aren’t on hormonal contraceptives tend to prefer the scent of men whose immune genes are different from their own. This makes biological sense: pairing with someone immunologically dissimilar could produce offspring with broader immune protection.
Women on the pill show the opposite pattern. In a study published in Proceedings of the Royal Society B, researchers tracked women before and after they started oral contraceptives. After beginning the pill, women’s scent preferences shifted significantly toward men with similar immune genes. Women in the control group, who didn’t start the pill, showed no such shift. The implication is that hormonal contraception may quietly steer you toward partners you’d find less appealing at a scent level if you weren’t on it.
This doesn’t mean you’ll suddenly dislike your partner’s smell. Scent is just one of many factors in attraction, and how much it actually drives real-world partner choice is still debated. But it’s the most consistently replicated finding in this area of research.
The Facial Masculinity Claim Doesn’t Hold Up
You may have heard that women on the pill prefer less masculine-looking men. Early studies suggested this, but newer and more rigorous research has failed to confirm it. A large study of 340 women randomized to either oral contraceptives or placebo, following a pre-registered analysis plan, found no significant effect of the pill on preferences for masculine or symmetrical male faces. Pre-registered exploratory analyses also found no link between menstrual cycle phase, hormone levels, and facial preferences.
A separate study with a large sample found that women on oral contraceptives showed no weaker preference for masculine male faces compared to women not using hormonal contraception. The difference that did appear was in how women rated other women’s faces, not men’s. So the popular idea that the pill makes you prefer “softer” looking men doesn’t have strong scientific backing.
What Happens to Mood and Energy Around Ovulation
Women who cycle naturally experience a measurable boost in positive mood, alertness, enthusiasm, and energy during ovulation. This spike doesn’t happen in women on hormonal contraceptives, because they don’t ovulate. Research comparing the two groups found that naturally cycling women scored significantly higher on positive affect during the ovulatory window, along with lower negative mood. From an evolutionary standpoint, this burst of energy and sociability may have evolved to increase mating opportunities during peak fertility.
For women on the pill, mood stays relatively flat across the cycle. This isn’t necessarily a negative. Some women prefer the emotional stability. But if you’ve noticed that you feel less of a “spark” or less flirtatious energy than you expected, the absence of that ovulatory boost could be part of the picture.
Starting or Stopping the Pill Can Affect Relationship Satisfaction
Some of the most practical research on this topic involves what happens when your contraceptive status changes within an existing relationship. The core idea, sometimes called the “congruency hypothesis,” is straightforward: if you chose your partner while on the pill, your preferences at the time matched your hormonally altered state. If you later stop taking the pill, your preferences shift, and your partner may no longer match them as closely.
The data supports this in a specific way. Women whose current pill use matched their use when they first got together reported higher sexual satisfaction. Women who met their partner while on the pill but later stopped were less sexually attracted to their partner and less sexually satisfied than women whose status stayed the same. Notably, this effect was limited to the sexual side of the relationship. Non-sexual relationship satisfaction, like feelings of emotional closeness or partnership quality, wasn’t consistently affected.
Marital Satisfaction and Partner Attractiveness
Two longitudinal studies of married couples revealed a striking pattern. Among women who were on hormonal contraceptives when they started dating their husband, stopping the pill had very different effects depending on how physically attractive the husband was. Women who stopped the pill and had a more attractive husband became more satisfied with their marriage. Women who stopped the pill and had a less attractive husband became less satisfied.
In other words, the pill may act as a kind of equalizer for physical attractiveness. While on it, a husband’s looks had little connection to his wife’s satisfaction. Once off it, attractiveness started to matter more. This didn’t work in the other direction: starting the pill during a marriage showed no consistent link to changes in satisfaction.
Libido and Sexual Function
Hormonal contraceptives lower circulating levels of androgens, estradiol, and progesterone, all of which play roles in sex drive. Some research also points to reduced neural response to erotic cues and changes in pair-bonding behavior. These biological shifts can translate to lower libido for some women.
That said, study results are genuinely mixed. Some women report no change, and others actually report improved sexual function, possibly because reduced pregnancy anxiety makes sex more enjoyable. The inconsistency across studies likely reflects real individual variation. Your response depends on the specific formulation, your baseline hormone levels, and psychological factors that are hard to isolate in a lab.
Putting It in Perspective
The strongest evidence for birth control affecting attraction involves scent preferences shifting toward immunologically similar partners. The weakest evidence involves changes in preferences for masculine faces, which recent controlled trials have largely debunked. The relationship satisfaction data is compelling but involves relatively modest effects that show up mainly in the sexual dimension of partnerships, not the emotional one.
If you started a relationship on the pill and are considering stopping, the research suggests your perception of your partner’s attractiveness may shift somewhat, particularly their physical and sexual appeal. This doesn’t mean your relationship is built on a hormonal illusion. Attraction is layered, and the components influenced by the pill (scent response, ovulatory mood shifts, baseline libido) are just a few threads in a much larger fabric of compatibility, shared history, and emotional connection.