Answers to the questions people actually ask. If yours is not here, write to info@huahuahua.io — a person reads it, usually within two working days.
Setting up
Enter the dose you are taking now as your current dose. Under First reduction choose In 14 days (or whatever your interval is) so step 1 is that dose. Then set Started to the first day you took it. The caption under Started tells you which day of the step that makes today — adjust the date until it matches.
With First reduction: Right away, step 1 is your first cut, so a 10% plan from 40 mg opens at 36 mg. Your current dose is where the taper starts from, not a step of it. If you want fourteen days at 40 mg first, choose In 14 days.
Presets write a typical label strength, and strengths differ by country and manufacturer. The field is always editable — type what your label says. Everything in mL depends on it, so check it before you create the schedule.
Both are ways of writing down a plan. Same % of dose takes the same share off the dose every step; what that costs at the receptor grows as the dose falls, and the drop to zero is the largest step. Same % of receptors takes the same share of receptor occupancy every step, the drop to zero included; in milligrams that is a large first cut and tiny last ones. It needs a medication family, because it uses that family's occupancy curve. Neither is a recommendation.
The app works it out from the numbers above it: 2.5% of your current dose by default, or — with a medication family — the dose whose drop to zero costs the receptors no more than the plan's largest step. It is your prescriber's number to change; type over it.
Following the plan
One mark on your syringe is a fixed number of milligrams. Far enough down the curve a 10% cut is smaller than one mark, so the dose would stop moving. Before that happens the plan has you mix a weaker solution — one part solution to one, four or nine parts water — so a mark is worth less and every step stays a real reduction. Today shows a card on the day a new mix starts, and the Curve marks it with a ring.
An estimate, from PET studies of volunteers, of the share of serotonin transporters a dose is blocking. It is a population average, not a measurement of you — which is why it says est. It is shown because a 10% cut at a high dose barely moves it and a 10% cut at a low dose moves it a lot; the curve makes that visible.
Choose Syringe marks in Setup and pick the marks your syringe has (0.01, 0.05 or 0.1 mL). Every dose then lands on a mark, and the plan dilutes when it needs to. Exact dose shows the true arithmetic to more decimals than a syringe can draw, for people whose prescriber is handling the measuring.
On Today, Rough patch? See your options shows the three things prescribers commonly consider — hold this dose, slow the rate, go back one step — with the new last-dose date for each. They are free to use. The app does not pick for you.
Reminders are local notifications. Check iOS Settings → Notifications → Stop SSRI is allowed, and that the time in the app's Settings is what you expect. Step-down, evening and weekly reminders are part of the unlock; the daily dose reminder is free.
Purchases
Free, and it stays free: the whole calculator, today's dose, the curve, the hold and slow-down options, and a one-page PDF of your schedule. The one-time unlock ($19.99, never a subscription) adds daily check-ins, the symptom chart, the extra reminders, and your scores and symptoms on the prescriber page.
Settings → Cannot afford it? Unlock for free. One tap, no questions, nothing to prove. It is kept on the device, so repeat it on a second device if you need to. If you can pay later, the purchase is still there.
Settings → Restore a previous purchase. Make sure you are signed in with the same Apple Account you bought it with.
Your data
Your plan is kept in your own private iCloud, so a fresh install downloads it again. To start over, use Settings → Delete everything inside the app; that removes it from iCloud too.
On your phone, and in your private iCloud database, which we cannot read. There is no account. Optional anonymous statistics contain counts only. The privacy policy lists exactly what is sent.
Settings → Delete everything. That removes the plan from your phone and your iCloud, and — if anonymous statistics were on — sends an opt-out that asks for the anonymous rows to be deleted. There is nothing else.
Something is wrong
Please tell us — this is the one thing we most want to hear. Email info@huahuahua.io with the medication, concentration, syringe marks, percentage, interval and final dose you entered, and the step you think is off. Never share a medical detail you would rather not; the settings are enough to reproduce it.
Same address. A screenshot and your iPhone model help.