About This Project

Hi, I'm Erica. I'm a trans woman with a peritoneal flap neovagina, and I've been on estrogen-based HRT for several years. For most of that time I was on a standard static protocol: the same amount of estradiol every week, progesterone every night, levels held as steady as possible.

It worked. It kept me in range. But cis women don't have static hormones. Their bodies cycle through a rhythm of estrogen rising and falling, progesterone appearing and disappearing, and a whole endocrine conversation that repeats roughly every 28 days. Static HRT doesn't try to replicate that. It holds you at a midpoint and calls it good enough.

I wanted to find out what happens when you try to mimic the cycle instead.

Why cycling?

Partly clinical curiosity. There's scattered evidence hinting that cyclic and continuous protocols aren't equivalent. In postmenopausal cis women, sequential (cyclical) progestogen exposure has been associated with lower breast cancer risk than continuous combined use across multiple large cohort studies (Brusselaers 2018, Fournier 2007, Lyytinen 2009). Cyclic progestogen has also shown bone-protective effects in premenopausal cis women with ovulatory disturbances (Prior 1994). None of this has been studied in trans women. The clinical relevance of cycling estradiol itself (rather than just scheduling the progestogen) is also unstudied. The hypothesis that replicating the full rhythm could produce different outcomes is reasonable, but it's an open question, not an established finding.

Where I cite clinical literature on this site, it draws heavily from studies of postmenopausal cis women on menopausal hormone therapy. That's the closest available reference population. Post-gonadectomy trans women and postmenopausal cis women are both hypogonadal: negligible endogenous sex hormone production, entirely dependent on exogenous dosing. The pharmacokinetic and endocrine baselines are comparable in ways that premenopausal cis women's aren't. Where the comparison breaks down (surgical anatomy, receptor exposure history, age-related differences), I note it.

Partly personal. There's something about your body doing what it's supposed to do, following a rhythm that aligns with who you are, that matters in a way that's hard to capture in a blood panel. I wanted to know if cycling felt different. If my body would respond. If having a hormonal month, with everything that comes with it, would feel like something worth having.

It does. That's why I'm writing this.

What this is

A detailed, patient-reported case study. One person (me) documenting a self-designed cyclical hormone protocol in real time. I track hormone levels using at-home urinary metabolite testing and periodic serum blood draws, log symptoms daily, and report what I observe with as much rigor as I can manage without formal clinical training.

Every cycle gets its own write-up: the data, the adjustments, and the subjective experience of living through it. I'm not smoothing anything over. Failed experiments, bad days, and protocol changes all get documented.

What this isn't

Medical advice. I'm not a clinician, an endocrinologist, or a researcher. I'm a patient with a detailed protocol, some paired calibration data, and the willingness to write it all down.

Nothing here should be taken as a recommendation to replicate without working with a provider who understands what they're looking at. The dosing, timing, and monitoring on this site were designed around my specific physiology: my absorption rates, my pharmacokinetics, my surgical anatomy. Your body isn't my body.

Who this is for

If you're a trans woman considering cyclical HRT and wondering what it actually looks like in practice, this is for you. Not as a template to copy, but as a reference point that barely exists in the patient-reported literature.

If you're a clinician or researcher looking for granular, longitudinal patient data on cyclical protocols in trans women, this is also for you. I'd love for this to end up as a footnote in someone's IRB application someday. The formal studies need to happen, and sometimes they start with someone saying "look, here's what I observed."

If you're here to tell me this isn't real or doesn't count, cool. I have better things to do than convince you. But if you feel the need to email me about it anyway, just know that I will absolutely make fun of you.

Contact

If you're a researcher interested in this data, or a provider working with patients on similar protocols, reach me at admin@secondcycle.io. I'm open to sharing additional detail in a confidential context that I wouldn't publish here.

References

Brusselaers, N., Tamimi, R. M., Konings, P., Rosner, B., Adami, H.-O., & Lagergren, J. (2018). Different menopausal hormone regimens and risk of breast cancer. Annals of Oncology, 29(8), 1771–1776.

Fournier, A., Berrino, F., & Clavel-Chapelon, F. (2007). Unequal risks for breast cancer associated with different hormone replacement therapies: Results from the E3N cohort study. Breast Cancer Research and Treatment, 107(1), 103–111.

Lyytinen, H., Pukkala, E., & Ylikorkala, O. (2009). Breast Cancer Risk in Postmenopausal Women Using Estradiol–Progestogen Therapy. Obstetrics & Gynecology, 113(1), 65–73.

Prior, J. C., Vigna, Y. M., Barr, S. I., Rexworthy, C., & Lentle, B. C. (1994). Cyclic medroxyprogesterone treatment increases bone density: A controlled trial in active women with menstrual cycle disturbances. The American Journal of Medicine, 96(6), 521–530.