Piel

Privacy Policy

Last updated: September 19, 2026

Piel ("Piel", "we", "us", or "our") is operated by Kan Consult s. r. o., a company based in Slovakia, which is the data controller for the personal data described in this policy. Piel builds a skincare companion app that checks the cosmetic and skincare products you own against your personal skin profile. This Privacy Policy explains what information we collect, how we use it, and the choices you have. It applies to our mobile apps, our website at mypiel.app, and related services (together, the "Service").

Information we collect

• Account information. When you create an account we collect your email address and authentication identifiers. If you sign in with Apple or Google, we receive the basic profile information you authorize (such as your name and email) to create and secure your account. We do not receive your Apple or Google password.
• Skin profile. Information you choose to provide about your skin — such as skin type, goals, sensitivities, allergens, and pregnancy status — so we can personalize product verdicts. You can edit or delete this at any time.
• Product and usage data. Products you search for or save; routines you build; and reactions you log. We also collect basic device and app-usage information (such as app version, device type, and crash diagnostics) to keep the Service reliable.
• Purchase and subscription data. If you buy Piel Premium, we receive your subscription status, plan, and renewal or expiry dates from the store you bought it through — Apple's App Store or Google Play — so we can unlock paid features on your account. Payments are processed by that store — we never receive or store your card number or other payment details.
• Progress photos (optional). Photos you take to track your skin over time are stored on your device. They stay there unless you turn on backup, which uploads copies to your account; turning backup off deletes those copies, and the photos on your device stay. Backup is off until you turn it on.
• Approximate location (optional). If you allow it, we use your device's approximate location to look up the current UV index where you are, so Piel can tailor its sun-protection guidance. Location is used only while the app is in use, never in the background, and we do not keep a history of where you have been. You can decline or revoke this at any time in your device settings, and the rest of the app keeps working. The lookup itself is made by Open-Meteo, a third-party weather service: your approximate coordinates are sent to it so it can return the UV index for that place. It receives nothing else about you — no account, no skin profile, no identifier — and Piel keeps no history of the locations it looked up.
• Website analytics. Our website at mypiel.app uses Google Analytics 4 to understand how visitors use the site, so we can improve the landing page. This is website-only — it does not apply to the mobile app. For each page you view, Google collects the page itself, plus its own standard signals: your approximate location derived from your IP address, your device and browser type, and the site that referred you. We do not use it for advertising — no advertising storage is enabled, and we do not run ads. In the European Economic Area, the United Kingdom and Switzerland, Google does not set an analytics cookie by default; analytics storage is denied there under Google's Consent Mode, so it receives only a cookieless signal. Everywhere else, an analytics cookie (named _ga and _ga_*) is set automatically. Google Analytics keeps the detailed, event-level data for 2 months and user-level data for up to 14 months, the retention periods set on our property, and deletes it after that; the aggregated reports we look at are not affected by those periods. Google Ireland Limited processes it for visitors in the EEA, the UK and Switzerland, and Google LLC processes it elsewhere. To opt out, install Google's Analytics Opt-out Browser Add-on, which stops your browser sending data to Google Analytics on any site. Blocking cookies in your browser is not the same thing: it prevents the analytics cookie from being stored, so visits are no longer linked together, but a cookieless signal can still reach Google Analytics.

How we use your information

• To provide, personalize, and improve the Service, including product verdicts.
• To create and secure your account and authenticate you when you sign in.
• To diagnose problems, prevent abuse, and keep the Service safe.
• To communicate with you about your account and important changes to the Service.

We do not sell your personal information, and we do not use your skin profile for advertising.

Piel assistant

Piel Premium includes an assistant you can ask about the product in front of you. It is off until you turn it on: the first time you open it, Piel shows you a consent screen setting out everything in this section, and nothing is sent to anyone until you agree. If you decline, the rest of the app works exactly as before.

Who writes the answers. The assistant's answers are written by a model run by Anthropic, a company outside Piel. Anthropic is our sub-processor: it processes this data on our behalf and on our instructions, under an agreement with us. These requests are processed in the United States, whichever country you use Piel from. That is Anthropic's region and not an answer for the other two recipients named below: we have not established where INCI API or Open Beauty Facts process what is sent to them, and we would rather say so than let one sentence stand for all three.

What Piel sends with each message. Only the following leaves your device:

• The product in front of you — its name and brand, the full ingredient list as Piel holds it, and Piel's own notes on individual ingredients.
• Piel's read on it — the Halo band, how much of the formula Piel could match, and every reason sentence on the screen, including the ingredient each one names.
• What Piel knows about you. Your skin type, whether your skin is sensitive, every skin goal you picked, and the follow-up answers you gave about the kind of breakouts you get and where your dark spots came from. Piel also says whether you have recorded a skin condition or a prescription treatment — never which one, though what Piel leaves out of your goal guidance can narrow it down. And it sends the reasons themselves: a reaction reason carries the ingredient you react to; a pregnancy reason says a pregnancy caution applies to you. That is your reaction history and your pregnancy status. This is health data about you, and sending it as reasons rather than as profile fields does not make it anonymous or de-identified.
• What Piel has reviewed for your goals. For each goal you picked, the ingredient families Piel's reviewed knowledge base holds for that goal, and the ingredients in them. That part is Piel's own reference material, not anything about you. Piel also says whether it listed every family it holds for that goal or only some of them — a family can be left out because it doesn't fit the answers you gave about your skin, or because something you recorded rules it out. It does not send which family was left out, or why. But it does send the ones it listed, and what is missing can be worked out from what is there. Leaving a family out of the message is not the same as keeping it private.
• The clashes in your routine, and only when you ask from there. Piel sends each clash it has found between two products you have added — the warning and the suggestion in the same words the routine screen shows you, how serious Piel rates it, and whether the two clash at the same time of day or only on the same day. Those sentences name ingredient families, so they say something about the products you own. Piel does not send the product names, and it does not send a clash you have already dismissed. Nothing from your routine is sent when you ask about a single product.
• The language you read the app in, so the answer comes back in it.
• Everything you type in the chat, including any health detail you choose to add that Piel never asked for.

Nothing else goes with it — except the routine clashes described above, when you ask from your routine. Your email address, your name, your account identifier and your reaction log are not part of an assistant request, and your other products are not sent with the message itself. If we ever need to send more than the list above, we will ask you to agree again first.

What the assistant can look up while it is answering. The assistant does not only read the message above. While it writes an answer it can ask Piel for more of Piel's own reference material, and it can reach three services outside Piel — INCI API, Open Beauty Facts, and Anthropic's own web search, each described below. It only ever reads: it cannot add anything to your shelf, change your routine, or alter your profile. Two of those three are capped per answer — at most two web searches, and at most one Open Beauty Facts lookup. The third, INCI API, is bounded by a metered allowance on the account rather than by a per-answer count, which is why it is named here rather than counted.

• Piel's own rows. Catalogue products that list an ingredient the answer is about — with the Halo band and reasons Piel has already worked out for you, so that lookup carries your profile too, and only ever reaches products your account is allowed to see; a product you named earlier in the same chat; and what Piel holds about a single ingredient.
• Piel's reviewed care lists. When your question touches pregnancy, a skin condition or a prescription treatment, Piel can tell the model two things: its own reviewed pregnancy caution list, which is the same list for everyone and does not depend on anything you recorded; and, if you have recorded a skin condition or a prescription treatment, the ingredient families to stay away from that follow from it. Piel never sends which condition or prescription you recorded, how serious it is, how many you recorded, or which of the two it was. Be clear about what that leaves open: those families are worked out from what you recorded, so the set of them can narrow down what it was. Not sending the name is not the same as keeping it private.
• INCI API — when Piel's own reviewed notes don't cover an ingredient on the product you are asking about. The assistant can send that product's ingredient list — the names only, nothing about you — to INCI API, a separate company that analyses formulas. What comes back is their read on each ingredient: whether they flag it as pore-clogging, as a common allergen, or as one to avoid in pregnancy, and which effects they consider well studied. Those are their findings and not Piel's, so the answer you read says whose they are. Piel keeps them for at most a day and then asks again, and it never saves them onto your product. This channel is not new with the tools — it has been part of the assistant since the previous version of this consent.
• Open Beauty Facts — when you name a product Piel's own catalogue does not hold. What leaves Piel is the brand and the product name, and nothing else: no profile, no findings of Piel's, none of your other products. What comes back is marked as Open Beauty Facts' and not as Piel's own read, because anyone can add a product there and the ingredient list may be partial or out of date.
• A web search, run by Anthropic — when a question about an ingredient or a rule goes past what Piel holds. What leaves is the words being looked up: an ingredient name, or the rule being asked about. Those words can come from your own message — if you ask about niacinamide, the search says niacinamide. What does not leave is your situation: not your profile, not Piel's findings about you, not the rest of what you wrote. The assistant is not offered a search at all when your question touches pregnancy, a prescription, a diagnosis, what caused something, or a child, because those are exactly the questions whose natural search would be about you.

The search is not restricted to four sites, and we will not tell you that it is. Piel asks Anthropic to stay on four reference sites: CosIng, the European Union's cosmetic ingredient database; the published opinions of the EU's scientific committee on consumer safety; PubMed; and the Cosmetic Ingredient Review. That is a request, not a boundary. Anthropic decides what comes back, and we have measured it returning other public pages too — medical article archives, trial registries, even a patent filing. Piel checks every source before showing it to you and names only those four sites, which means a source Piel will not name is one it drops rather than one it labels. So what Piel names is bounded and what the answer is informed by is not: the answer you read may have been informed by a page Piel did not ask for and does not name.

What is kept. Anthropic does not retain your messages under our zero-data-retention agreement. Piel keeps no chat content on its own servers either: nothing you type in the assistant is stored once the answer has come back, and your conversations are not carried between sessions. The one thing Piel does record is how many assistant messages you have sent on a given day, so it can apply a daily limit.

Two gaps in that, which we would rather name than leave you to assume. First: the zero-data-retention agreement covers the conversation, and we have not yet confirmed in writing that it also covers the words sent to Anthropic's own web-search tool — the ingredient name or the rule being looked up, described above. Second: that agreement is with Anthropic and reaches nobody else. INCI API and Open Beauty Facts are disclosures to separate companies rather than sub-processors working on our instructions, so an ingredient list sent to the first, or a brand and product name sent to the second, is held under their terms and not under ours. So a search term, an ingredient list and a product name are the things here we cannot promise are unretained. All three are still never your situation: not your profile, not Piel's findings about you, not the rest of what you wrote.

Answers are not reviewed. The model writes each answer as you watch, and Piel does not check it before you read it. An answer can be incomplete or wrong. Piel is not a medical service and does not give medical advice.

Turning it off. You can withdraw your consent to the assistant at any time in the app. From that moment Piel sends nothing further to Anthropic, and the daily message counts held for you are deleted. Withdrawing assistant consent leaves your skin profile and the rest of the app exactly as they are. Withdrawing your skin-profile consent, or deleting your account, also deletes those counts.

Reporting an answer. Every assistant reply carries a "Report this answer" link. If you use it, the answer you are reporting and the reason you pick are sent to us so a person can review them — and that is the one case in which any part of an assistant conversation is kept, because nothing else holds a copy of it. Nothing is sent until you pick a reason, we do not attach your name or email to a report, and we use reports to tighten what the assistant is allowed to say.

How your information is shared

We share personal information only with service providers who process it on our behalf (for example, cloud hosting, authentication, and crash-reporting providers) under agreements that require them to protect it, and when required by law or to protect the rights and safety of our users. We may share aggregated or de-identified data that cannot reasonably be used to identify you.

Google operates Google Analytics 4, which our website at mypiel.app uses as described under "Information we collect" above. Google processes this website-usage data as a service provider acting on our instructions — Google Ireland Limited for visitors in the EEA, the UK and Switzerland, and Google LLC elsewhere. This is website-only: analytics data is not sent from the mobile app.

The Piel assistant has three recipients outside Piel, and they are not the same kind of recipient. One processes your data on our instructions under an agreement with us; the other two receive an ingredient list or a product name and are not acting on our instructions at all.

Anthropic is one of those service providers. If — and only if — you turn on the Piel assistant, the information listed under "Piel assistant" above is sent to Anthropic so it can write an answer for you. That information includes health data about you. It is described in full in that section, and nothing is sent until you have agreed to it. Anthropic also runs the assistant's web searches, so the words Piel looks up go to Anthropic as well — an ingredient name or the rule being asked about, never your situation.

INCI API is the second, and it is the longest-standing of the three. When Piel's own reviewed notes do not cover an ingredient on the product you are asking about, Piel sends that product's ingredient list — the names only, nothing about you — so INCI API can return its own read on each one. Those are their findings and not Piel's, and the answer you read says so. Piel keeps what comes back for at most a day and never saves it onto your product. Like Open Beauty Facts below, this is a disclosure to a third party rather than a sub-processor arrangement.

Open Beauty Facts is the third, and only when you name a product Piel's own catalogue does not hold. Piel sends that brand and product name so it can tell you what is in the thing you asked about instead of asking you to go and scan it. Nothing about you goes with it. Open Beauty Facts is a public, openly licensed product database run outside Piel rather than a provider acting on our instructions, so treat this as a disclosure to a third party and not as a sub-processor arrangement — which is also why what comes back is labelled as theirs and not as Piel's own read.

Where our product and ingredient data comes from

Piel does not compile the cosmetics catalogue itself. Some of the product and ingredient information you see in the app comes from open databases, and we credit them here because their licenses ask us to. This is reference data about products, not about you, and none of your personal information is sent to these sources.

EU CosIng. What an ingredient is classed as doing in a formula comes from CosIng, the Cosmetic Ingredient Database of the European Commission. © European Union. We use it under the Creative Commons Attribution 4.0 license, and we changed the data: ingredient names are standardized and matched to Piel's own records, so what you read in the app is Piel's version of it. The European Commission had no part in Piel and does not endorse it.

Open Beauty Facts. Some product names, brands, photos and ingredient lists come from Open Beauty Facts, where they are available under the Open Database License. We changed this data too: names are standardized and ingredient lists are read again against Piel's own ingredient records.

The same sources back the public ingredient glossary on this website, at /ingredients and /es/ingredientes: each page shows CosIng's classification and identifiers for an ingredient, Piel's own family groupings and notes where a reviewer has stamped them, and how many products in Piel's own catalogue list it. Those pages are about ingredients, not about you, and carry no form and no account.

Data retention

We keep your information for as long as your account is active or as needed to provide the Service. When you delete your account, we delete or de-identify your personal data within a reasonable period, except where we must retain it to comply with legal obligations. Assistant conversations are the exception in the other direction: they are not stored at all, unless you report one — see "Piel assistant" above. Website analytics data is not held under this policy — Google Analytics keeps it under its own default retention period; see "Information we collect" above.

Your choices and rights

• Access, correct, or update your profile information from within the app.
• Delete your account and associated personal data at any time from the app settings, or by contacting us at the address below.
• Depending on where you live, you may have additional rights under laws such as the GDPR or CCPA, including the right to access, port, or delete your data, and to object to certain processing.

Security

We use industry-standard technical and organizational measures to protect your information. No method of transmission or storage is completely secure, but we work to protect your data and continuously improve our safeguards.

Children's privacy

Piel is not directed to children under 13 (or the minimum age required in your jurisdiction), and we do not knowingly collect personal information from them. If you believe a child has provided us with personal information, please contact us so we can remove it.

Changes to this policy

We may update this Privacy Policy from time to time. When we make material changes, we will update the "Last updated" date above and, where appropriate, notify you within the Service.

Contact us

If you have any questions about this Privacy Policy or your data, contact us at support@mypiel.app. Piel is operated by Kan Consult s. r. o., a company registered in Slovakia (IČO 57 860 157, DIČ 2123287815), with its registered seat at Štefana Hozu 1577/21, 053 11 Smižany, Slovakia.