Understand Female Desire, Attraction, and Partner Choice | Sarah Hill EP 227
In a Nutshell
Hormonal birth control dampens women's natural estrogen-driven preferences for masculine, genetically compatible male faces and scents, leading 20-30% of women to lose attraction to partners chosen while on the pill after discontinuing, potentially contributing to relationship dissatisfaction, infertility, and suboptimal offspring health. Naturally cycling women experience two hormonal phases: high estrogen in the follicular phase boosts sexual desire, energy, and partner discrimination for conception, while luteal-phase progesterone prioritizes pregnancy optimization, raising metabolism (needing 140-200 extra calories), threat sensitivity, and pair-bonding over raw lust. Sarah Hill's *The Period Brain* empowers women to embrace cyclical brain shifts for better health, mood, relationships, and identity—effects often misattributed to flaws until years post-pill, as receptors resensitize and false self-narratives rewrite.
These notes were generated by AI and may contain inaccuracies.
When women use hormonal birth control, they create a more feminized male face in digital programs testing ideal male faces, compared to naturally cycling women. Women have been led to believe the only way to promote an egalitarian society is to deny biological differences with men 100%. Most insights on heart attacks, good nutrition, and sleep requirements are based on research conducted in men. Beginning to understand what your brain and body are doing as you move between different cycle phases—what 50% of the population is female. Even men trying to avoid women will interact with them.
Sarah Hill, welcome back. This is exciting. New book, The Period Brain.
Dr. Sarah Hill is an evolutionary psychologist, researcher, and professor. She studies women's brains and psychology, specializing in women's hormones and hormonal changes influencing how women think, feel, and experience the world. Focuses on naturally occurring hormones and impact of hormonal birth control on women's psychology.
She taught a course at Peterson Academy on evolutionary approaches to human behavior, sex differentiation, biological differences between men and women, men's and women's hormones, and effects of hormonal birth control, which flatlines hormones and replaces them with synthetics. Covers evolutionary approaches, sex differentiation, neuroendocrinology, and the pill.
After previous podcast, information on birth control effects should be known by everyone, including men dating women. A clip on mate selection and birth control went viral on TikTok.
Research on women's endogenous hormones shows that when estrogen is rising and high across the cycle (when conception is possible), it increases attunement to cues of facial masculinity—qualities related to good genes. Quashing estrogen production with birth control leads to less preference for masculinized male faces. Women on hormonal birth control create a more feminized ideal male face than naturally cycling women.
Studies follow women who chose partners on the pill. A longitudinal study of married couples found changes in attraction when women went off the pill. For women married to highly attractive men (objective ratings), attraction increased—"blinders came off"—and relationship satisfaction rose. For women married to less attractive men, attraction decreased, and marital satisfaction dropped.
New study with Natural Cycles app (users off hormonal birth control, all former users): half chose partners on pill, half off. Women who chose partners off the pill had more frequent logged sexual behavior across cycles and higher levels of physical attraction. Estrogen primes brain to detect small differences in men for sexual attraction/desire. On pill, sexual desire dampened, less prioritization of attraction cues.
Changes in sexual desire after going off pill:
- ~40% no change in attraction.
- 20-30% more attracted (blinders off, detecting genetic compatibility, testosterone).
- 22-25% less attracted (mismatch from dampened desire on pill).
Recommendation: Don't choose marriage partner on pill as insurance policy, especially if not needed.
40% no difference doesn't confirm right choice—might have led to different outcomes.
Wonder if messing with evolution's mate choice impacts society genetically. Naturally cycling women prefer scent of genetically compatible men with different immune genes. Rising infertility (partly from delayed childbearing) might partly stem from choosing partners on pill, dampening sensitivity to genetic compatibility cues, leading to unexplained infertility.
One study: Women choosing partners on pill had children with more frequent doctor visits.
Ongoing research with cycle tracking apps: Whether choosing partner on/off pill affects time to conceive in trying-to-conceive mode.
Estrogen rises and peaks when conception possible for a reason—brain attuned to differences between men because it matters. Might affect 20-25% of cases.
The Period Brain is about what a naturally cycling female brain does. Women led to believe most feminist thing is ignoring hormones to deny biological differences. Book embraces female brain and hormonal changes across cycle, understanding what brain/body do in different phases, providing language to feel comfortable, understand body better, and eliminate PMS.
Health insights (heart attacks, nutrition, sleep, aging) based on men. Women included late, only in first days of cycle (low hormones) to mimic men and simplify data. Doesn't apply to second half of cycle, causing women to feel terrible last two weeks—sold bad bill of goods on body needs.
Cycle starts day 1 of period, hormones low—brain stimulates ovaries for egg follicles to prepare for ovulation. Maturing follicles release estrogen (primary sex hormone), orienting brain/body toward attraction and sex (peaks when conception possible). High/rising estrogen: higher sexual desire, more sex/interest in men, easily distracted by men/flirtation, feel sexier, more energy, smell/move/voice sexier to men—optimized for sex/attraction/partner discrimination.
Estrogen rises first 14 days (assuming 28-day cycle), peaks, ovulation day 14. Fertile window: 5 days before + day of ovulation.
Post-ovulation, estrogen drops; empty follicle becomes temporary endocrine structure releasing progesterone (second primary sex hormone). No ovulation, no progesterone.
If you don't ovulate, no progesterone. It's easy to disrupt ovulation, leading to many women's hormones being out of whack because they're not ovulating and missing the influx of progesterone, which is good for the brain and body.
Progesterone is released for 12-14 days, optimizing the body for implantation and pregnancy. Women's bodies cycle because they have two reproductive jobs: sex and pregnancy. Men have one hormone for sex. First half of cycle is about sex and attraction; second half, coordinated by progesterone, orients body for implantation and pregnancy, causing immunological, metabolic, and sexual shifts. Women aren't told about these, so they feel worse than needed.
Resting metabolic rate increases 7-11% in second half due to differentiating cells and building endometrial lining, raising body temperature (as in pregnancy). Naturally cycling woman needs additional 140-200 calories/day in luteal phase. Women follow one-size-fits-all guidelines, feel hungry, angry, have cravings, thinking something's wrong, but they're not eating enough.
Respiration rate increases with temperature, body baseline works harder, recovery takes longer in luteal phase. One-size-fits-all recovery/sleep standards leave women tired and low-energy.
Women's sexual desire peaks with estrogen, brakes applied when estrogen falls and progesterone rises—on purpose to conserve energy (metabolism up) and avoid inflammation from introducing nonself DNA near implantation site. Sex in luteal phase is more about connection and pair-bonding than scratching a sexual itch (first half).
Many women feel broken because their sexual desire is cyclical and they're not told this is normal. They feel their body is the enemy due to cravings and hunger.
Host started birth control at 14 for skin, on quarterly bleed pill (not real cycle) through teens/early 20s. Got off at 22-23 when focusing on health.
For reproductive-aged women, messed-up cycles often metabolic (e.g., PCOS from insulin resistance—addressing it normalizes cycles) or poor physical health. Promote health beyond food/exercise: manage stress. Stress hugely impacts hormones.
Body suppresses ovulation if environment unsupportive of pregnancy: assesses village/social support, stress management, energy intake, chronic inflammation, illness/vaccines (delays cycle couple days, not infertility). Steps to normalize: build community, nourish with healthy foods, minimize stress (brain doesn't think saber-tooth tiger den).
In research on healthy women (18-25, no endocrine disorders, regular 26-35 day cycles), 30% failed to ovulate that cycle. Colleagues confirmed typical ~30%, especially stressed college women. COVID isolation also suppressed ovulation—body avoids costly/risky pregnancy.
Bleeding Without Ovulation
You can bleed without ovulating: body starts process, matures follicles, proliferates endometrium; hormones support long enough to mimic cycle, then fall, causing period (not full cycle).
Feeling safe in relationship crucial hormonally for ovulation potential. Young women confuse danger vibes with excitement.
Progesterone increases attunement to lack of safety. Brain like smoke detector for threats; sensitivity rises in luteal phase as amygdala interconnects more, making women emotionally sensitive (not 'crazy'—safety mechanisms). Example: partner loads dishwasher wrong → brain questions safety/value of needs.
Advice: Ask if feeling upset is about safety/security worry. Have conversations for reassurance, improving relationships. Book helps with talks on desire changes, sensitivity, leading to intimacy.
Everyone needs this knowledge for relationships/friendships/marriage with women (50% population).
Men email about relief from chapter on cyclical desire: previously felt insecure/rejected, pestered partner, creating loops. Understanding it's normal (not undesirability/relationship issue) allows relaxation, reduces ego-driven pursuit.
Host off pill: shocked by heightened smell (like a dog), especially first half cycle. Mood fluctuations: fun first half, productive work second (fun-work cycle). Felt like worker ant on pill—head down, no distractions/pleasure. Off pill: more fun, same productivity, different rhythm. Likely contributed to depression.
Sarah: Same—heightened scent detection to masculinity metabolites (testosterone); lowers sensory threshold around ovulation, aids partner choice. Cycle shifts normal: externally facing/fun vs. buckle down/work. Don't fear losing productivity—ride the cycle, more fun, not less productive.
It took almost 10 years off hormonal birth control to rewrite narrative of being depressed/anxious.
Sarah Hill shares that it took over 10 years off the birth control pill to realize her experiences on it were not her true personality. She describes herself as gritty, feeling sad for a day after setbacks but quickly bouncing back, unlike her pill-influenced self where she did not get depressed easily.
The host echoes a similar experience, coming off antidepressants and birth control simultaneously, discovering she is extremely stress tolerant, contrary to her prior self-perception of being depressed and volatile.
Many women stay on birth control so long they do not discover their true selves until late in life. On the pill, they often feel "fine" or "great," only realizing post-discontinuation what they missed. Identity forms around medication-influenced behaviors during young adulthood, requiring years to rewrite.
Sarah felt low stress tolerance and easy depression on the pill, traits not aligning with her true self, taking 10 years to fully rewrite her narrative.
Recovery from birth control is mostly psychological. Hormonally, women resume ovulating and produce hormones at normal levels within 1-3 cycles. However, hormone receptors need time to resensitize after constant daily signals on the pill, which prevent adaptive adjustments like increasing or decreasing receptor numbers based on estrogen fluctuations.
The brain's plasticity helps, but identity adjustment is the bigger change. People lack innate self-insight and learn their traits by observing their own behaviors over time, similar to observing others. Building identity takes years of experience; overriding a decade of maladaptive responses requires more than a few months.
The host describes post-antidepressant and autoimmune recovery confusion: medication withdrawal led to identity flux. Initially super depressed, then hypomanic for a year—feeling great, shedding misplaced guilt, enforcing boundaries rudely without guilt, questioning if she was a "terrible person" who just didn't care. This stemmed from lacking a personality foundation, eventually stabilizing.
Antidepressants mess with neurotransmitter levels and receptors brain-wide, making withdrawal a major challenge requiring script rewrites.
Host praises the conversation, recommends Sarah's previous book, expresses surprise at learning the body can produce periods without ovulation due to estrogen-driven proliferation, even if no egg is released.
Sarah's book covers identifying true ovulation despite periods, supporting ovulation, and adapting to cycle changes.
Follow Sarah on Instagram at @SarahEHillPhD (Sarah with an H) or sarahehill.com.
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