You have options.
Here's what actually changes.

Oura Ring

Oura is strong at HRV, resting heart rate, sleep stages, and body temperature. The cycle-tracking feature is essentially a temperature-based prediction, useful if you're cycling regularly, silent if you're on hormonal contraception, in perimenopause, postpartum, or post-hysterectomy.

Oura also can't ingest a blood test, doesn't know your HRT regimen, won't discuss PMDD or endometriosis, and has no editorial voice. The score is the answer, and the answer is a number.

Whoop

Whoop is built for athletic training loads. It's strong at HRV-based recovery scoring and daily strain targets. The women's-health module was added later. It tracks cycle phase and gives phase-based training guidance, which is helpful if you're a competitive athlete timing hard sessions to your follicular window.

What Whoop won't do: talk about hot flashes, HRT dosing, PMS or PMDD as clinical entities, perimenopause bone or heart risk, or preventive-care schedules. It's a performance product with a cycle add-on, not a hormone companion.

Apple Health

Apple Health is a comprehensive personal-health data store. It aggregates sleep, HRV, steps, cycles, workouts, and medical records, and it stores lab results if your hospital uses Apple Health Records.

But Apple Health does not interpret. It gives you numbers and charts. It doesn't say "your sleep is running short this week and you're in late luteal, protect tonight." It won't build a doctor-ready PDF, won't remember a symptom pattern, and won't answer questions about HRT.

ChatGPT or Claude with a Health connector

You can pipe Apple Health into a general-purpose AI and ask it anything. The answers can be surprisingly good. But four things break down at scale:

Memory. A new conversation starts empty. Your cycle history, past labs, HRT regimen, and last week's symptoms don't carry over unless you re-paste them every session.

Context. The model doesn't know you're perimenopausal, or that your progesterone dose changed last month, or that your ferritin was 22 in April. You have to hand it that context every time.

Privacy. Everything you share becomes part of a conversation on a general-purpose consumer AI account tied to your email. Training-opt-out policies vary by provider, and defaults change over time; the safest assumption is that anything you paste in is retained on the account.

Editorial voice. A general chatbot doesn't know Kriva's rules: no streaks, no nags, no fabricated data. It'll happily invent a plausible-sounding pattern from thin evidence, because that's what LLMs do when you ask them to interpret.

Flo, Clue, Natural Cycles, and the rest

These apps are why hundreds of millions of women log cycles on a phone. They're good at prediction, symptom logging, and community. What they're not built for: the transition out of cycling. Once you enter perimenopause, most cycle-app UI stops making sense: the ovulation graph, the "next period in N days" widget, the fertility framing.

Data-handling records for this category are mixed. Some sell aggregated cycle data to third parties. Some have been subpoenaed. Most require an email account to use.

Your clinician's portal

Your labs live on MyChart, Cerner, or whatever portal your practice runs. You log in when a result is ready, glance at the flags, and log out. The next time you visit, you're re-explaining the same symptom timeline you explained last visit.

Portals don't trend your labs across dates, don't correlate with your symptoms, and don't build a summary you can hand back to a clinician for the next appointment.