This suite was written for one specific body: cis men having sex with men. That focus is what makes the advice precise — same core anatomy on both sides, no pregnancy pathway, exposure routes that don't jump between fundamentally different systems. But it also means some of it doesn't transfer, and a few things could actively point you in the wrong direction if you apply them outside that context.

This article maps what transfers and what doesn't, so you know what to use and what to leave behind.

What Still Holds

The physical game is not all of the game — while the anatomy-specific guides don't transfer, the psychology section, most of strategy, and most of reactive very much do.

The entire psychology section is about behaviour and decision-making, not bodies. Consent communication, partner vetting, green-flag and red-flag patterns, boundary assertiveness, navigating shame and clinic avoidance, relationship protocols, supporting a friend in crisis, recognising compulsive patterns, sober sex — none of it depends on anatomy or the gender of your partners.

Most of the strategy section holds too. The buddy system, chemsex and drug safety, drug interaction warnings, app hookup strategy, group sex safety, how to talk to a doctor — behavioural or pharmacological, context-independent. What doesn't: the mechanics guides (bottom, top, versatile, fisting) and the lube guide, which are calibrated for rectal tissue and MSM-specific dynamics.

Most of the reactive section transfers — PEP, DoxyPEP (with the pregnancy note below), STI diagnosis and treatment, partner notification, overdose and spiking emergency protocols. The exception is the anal injury triage guide, which is rectal-specific.

The prevention-framework content — prevention stack, HIV facts, U=U mechanics, vaccines, STI landscape, pre-travel health — is not MSM-specific. The vaccine article skews its cancer framing toward anal and penile risks; the vaccine recommendations themselves are universal.

The content that doesn't transfer is in the sections below.

If You Also Sleep With Women

Most of the stack holds — PrEP, quarterly testing, vaccines, the testing mandate. Two things don't transfer cleanly.

Lube: The lube guide is calibrated for rectal chemistry. Don't use it as a reference for vaginal sex — most anal-friendly lubes (PEO-based, or thicker water-based formulas) sit at a neutral pH around 7 to match rectal tissue. Put that in a vagina and you knock its naturally acidic environment (~pH 4) out of balance, which is enough to trigger irritation or bacterial vaginosis. Use a lube formulated for vaginal use instead: iso-osmolar, glycerin-free, pH ~4.0–4.5. Keep separate lubes if you're switching contexts in one session.

DoxyPEP: One thing this guide never mentions because it's irrelevant in an MSM context — doxycycline isn't safe to take during pregnancy. It crosses the placenta and can permanently stain a developing baby's teeth and interfere with bone growth, so it's avoided the same way other tetracycline antibiotics are. If pregnancy isn't reliably ruled out, check with your doctor before using it.

Your testing rhythm and sites don't change. The testing protocol still applies for what you've been exposed to.

If You're Trans, or Your Partner Is

This suite assumes cis male anatomy throughout — penis, testes, rectum, no uterus. Some of it will fit and some won't.

The fiber protocol: The two-hour spacing rule for psyllium and PrEP applies to all oral medications, including HRT. If multiple oral medications are taken throughout the day, the timing must be coordinated before settling on a fiber schedule.

Neovaginal care: Neovaginas don't come with a universal standard. The physical characteristics, bacterial flora, and care instructions depend entirely on how the specific surgery was performed and what tissue was used. Because of this, the lube chemistry, douching mechanics, and rinsing advice here (which are calibrated for rectal tissue) do not transfer. The particulars of neovaginal anatomy are best explained by an expert — ideally the clinician in the country where the operation was performed, or a provider with genuine experience in that specific procedure.

Oral PrEP timing: The 7-day startup window for oral PrEP in this guide is validated for rectal tissue. For vaginal tissue, the lead time is longer — it takes about 21 days of daily dosing to establish full protection. For neovaginal tissue, the clinical data basically doesn't exist yet, and how fast the drug absorbs depends entirely on what kind of tissue was used to build it (e.g., skin graft vs. colon). Because there is no universal timeline, the safest move is to treat 21 days as the absolute minimum baseline and consult a provider to map out the rest. Plan accordingly.

PrEP with feminizing hormones: If you're on estradiol, don't use on-demand (2-1-1) dosing — hormones may lower tenofovir levels enough that the event-driven schedule isn't reliable. Daily oral PrEP and injectable PrEP both work alongside HRT, and PrEP doesn't reduce hormone levels.

Testosterone isn't contraception: If you have a uterus and vaginal sex is part of your picture, pregnancy is still possible on testosterone. The DoxyPEP pregnancy warning above applies to you — check with your doctor before using it.

Vaginal tissue on testosterone: Testosterone thins vaginal tissue and reduces natural lubrication, making it more prone to friction tears. Neither the rectal lube guidance here nor standard vaginal lube advice fits exactly — use lube generously, choose glycerin-free, and ask your provider what suits your tissue.

Testing: Test where you've had exposure. If vaginal sex is part of your picture, a vaginal or cervical swab belongs on your panel alongside the standard testing protocol. If you've had vaginoplasty, ask your sexual health provider what swabs are appropriate for your anatomy — standard panels weren't designed with that in mind.

The Short Version

If the anatomy or context doesn't match a cis man having sex with men, treat this guide as partial. The core framework — PrEP, regular testing, friction management — transfers broadly. The specific recommendations often don't. For anything outside this guide's scope, use resources written for your situation.

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