A woman in her mid thirties in an ivory silk camisole, a beam of warm sun across her cheekbone, against a golden plaster wall.

The fourteen day issue

DermProof. Your serum makes a claim. Make it prove it.

DermProof measures your skin against your own baseline for fourteen days, then tells you plainly whether each product did what the bottle promised.

One email when TestFlight opens. Nothing else, and no sharing.

p. 02 · In this issue

No lamp to buy. No account. Nothing leaves your phone.

11
skin metrics measured per capture
8
face regions analysed separately
14
days before any claim gets a verdict
0
photos or pixels uploaded anywhere
Close up of a woman’s cheek, ear and jaw in a beam of golden sun, freckles and pores sharp, eyes closed.

p. 03 · Feature 01 · The problem

You cannot see a 4% change in your own face.

Skin moves slowly, and memory is not an instrument. Every bottle is “clinically proven” on somebody else, and two selfies are not a trend: the light, the angle or the day you chose can change the answer entirely.

Nothing you own tells you what a product did for you.

p. 04 · What people are saying

Nine things people say about skincare, and what DermProof does about each.

Real posts, word for word. Each one is a change sitting somewhere near the line, with nobody able to say which side.

  1. 01 · A slow change

    “you don’t notice them working until you remove them and your baseline slips a bit”
    u/BlendedNotPerfect, r/AsianBeauty

    A measured baseline on day 0. Every later change is judged against it and against your own noise floor, not against memory.

  2. 02 · No idea if it did anything

    “I just don't see ANY benefit from it versus when I don't have it in my routine.”
    u/sn4rfsn4rf, r/SkincareAddiction

    A plain answer at day 14. Supported, or Not supported. Worth knowing before you rebuy.

  3. 03 · How long to give it

    “i haven’t seen any improvement with it, but i wasn’t sure if i should give it more time.”
    u/zombifever, r/SkincareAddiction

    A first verdict at day 14. If the data is still too thin, it says “Needs more time” instead of guessing.

  4. 04 · Which one did it

    “bought like 10 products at once and my skin freaked out, couldn't even tell which one was causing problems”
    u/Negative_Pie2654, r/AsianBeauty

    One tap logs the routine you actually did, so a change can be attributed to a product rather than to luck.

  5. 05 · Brand photos

    “NOT TO MENTION FILTERS AND GOOD LIGHTING”
    u/cashewmonet, r/AsianBeauty

    No filters, no flattering after shot. Exposure, white balance and focus are locked before the shutter and recorded with every photo.

  6. 06 · Photos never match

    “I know the lighting isn't exactly the same, but hopefully the difference is visible”
    u/Dapper_Damage_8265, r/SkincareAddiction

    Guided capture keeps week six comparable to week one, and each reading is weighted by how good the photo was.

  7. 07 · Viral means paid

    “Best thing I did was stop buying products that go viral on TikTok. They’re literally paid advertising.”
    u/abz_pink, r/AsianBeauty

    DermProof sells nothing, takes no affiliate revenue and recommends no products. The only reviewer is your skin.

  8. 08 · Will it work for me

    “As with all skincare, it’s very much a ymmv thing.”
    u/TastingTheKoolaid, r/Sephora

    Your verdict comes from your face, not the crowd. With Derm Duo, two people can run the same product and see two answers.

  9. 09 · Slow and hard to keep

    “it can take up to 40 days for skin to get acclimated to new products. 40 days!”
    u/panda88panda, r/AsianBeauty

    The app keeps the record for you: two minutes on day one, a tap to log, ninety seconds a week to check in.

Quotes from public Reddit threads, March to September 2026. The answers are ours.

Profile of a woman in her late twenties in hard Mediterranean sun, eyes closed, the sea behind her; pores, freckles and fine facial hair in sharp detail.

p. 05 · Feature 02 · How it measures · Private, on the device

The camera is easy. Making two photos comparable is the work.

  1. 01
    Capture, locked

    Exposure, white balance and focus locked before the shutter, and recorded with the photo.

  2. 02
    Your noise floor

    Several baseline frames, seconds apart. Their spread is the bar every later change must clear.

  3. 03
    Every reading, weighted

    A trend across all your check ins, weighted by capture quality. One bad photo cannot flip it.

  4. 04
    Weather, ruled out

    Humidity, UV and season recorded with each reading. If the weather explains it, the verdict is withdrawn.

Private, on the device. All analysis happens on your iPhone. No account, and 0 photos uploaded.

p. 06 · The fine print

No account. No upload.

There is no DermProof login because there is no DermProof copy of your face. Backup is your own iCloud and a file export you control.

Never leaves your iPhone

  • Every photo you take, baseline and check in
  • All pixel analysis. Private, on the device.
  • Your metrics, routine logs, notes and product shelf
  • Your identity. There is nothing to log in to.

Leaves only if you switch it on

  • An anonymous row saying a claim was supported or not. No photos, no identity.
  • A Duo pairing code, anonymous, metric deltas only.
  • Coarse weather context for your region.
  • One tap deletion removes the anonymous rows too.

p. 07 · Feature 03 · The ritual

Keep the ritual. Add the record.

Two minutes on day one. Ninety seconds a week after that.

A woman in her late twenties with a short brown bob and a white linen shirt sits in a stone window seat above the sea, phone in her lap.

Day 0 · Baseline

Begin with you.

A guided capture of about two minutes. Then add the products you already own, and what each one claims.

An East Asian woman in her twenties in a camel knit holds an unlabelled dropper bottle and touches her cheek in a warm room.

Days 1 to 13 · Log

Live your routine.

A tap records the routine you actually did. One 90 second check in a week.

A serum bottle, a glass of water and a phone lying face down on sunlit travertine.

Day 14 · Verdict

Read the answer.

A verdict for each claim, or an honest “Needs more time.”

A man in his late twenties with a towel around his neck rests a hand on his cheek after shaving, in pale water light.

Ongoing · The record

Let it compound.

Every week sharpens the trend. Your next product starts against a measured before.

For a fair reading

Check in at the same spot, in the same light, every time. Skipping alcohol on check-in days helps too.

No lamp, scanner or stand. The iPhone you own is the instrument.

p. 08 · Beneath the surface

The claim on the bottle, read on your face.

Each claim is matched to the metric behind it. Eleven skin metrics on every capture, eight face regions analysed separately, all of it on your iPhone.

A woman in her thirties with her eyes closed and hair pinned up, water light rippling across her cheek, a stone spa pool behind her.
  1. 01Hydrating

    Read as hydration on every capture, and judged against your own noise floor.

  2. 02Brightening

    The metric behind the claim has to move past your noise floor, or it is not called a result.

  3. 03Pore minimising

    Logged against the routine you actually did, so a change lands on the right bottle.

  4. 048 regions, 11 metrics

    Eight face regions, each analysed separately. Eleven skin metrics measured per capture.

p. 09 · Feature 04 · All four possible answers

Three of them are not “it works.”

Every verdict carries an uncertainty interval and an evidence strength. Evidence strength describes your data; it is not the probability that a product works.

  • Supported

    It did what it claimed.

    The metric behind the claim moved the right way, by more than your noise floor, and the trend held across your check ins.

  • Not supported

    It didn’t.

    Fourteen days of your own data, and the claim did not show up. Worth knowing before you rebuy.

  • Needs more time

    We can’t say yet.

    The movement is inside your noise floor, or there are too few good captures. Silence beats a guess.

  • Withdrawn

    The weather explains it.

    When humidity or UV tracks the change as closely as the product does, the verdict is pulled back.

A woman in her late twenties in a white waffle robe rests her cheek on her hand at a sunlit spa vanity.

p. 10 · Honest results

Beautiful is knowing.

DermProof sells no skincare and takes no affiliate revenue. The answer has nothing to sell you.

p. 11 · Portfolio · Same bottle, different skin

Measured on your face. Not on someone else’s.

A trial average across strangers says nothing about your skin, your climate or the four other things you put on your face that morning. Your verdict comes from your own baseline.

A Black woman in her mid twenties with natural shoulder length coils and navy tailoring holds her iPhone up for a guided photo.
Day 0.Her baseline, and her own noise floor.
A woman in her early thirties with thick dark hair in a low knot, in a navy satin slip and charcoal jacket, laughing with her phone in her hand.
Day 14.Her answer, from her own data.
A woman in her early sixties with a cropped silver bob and a charcoal turtleneck, fingertips on her cheekbone, smiling to herself.
Week after week.Her record compounds.

p. 12 · Derm Duo · Free, and staying free

Same product, two faces, two answers.

Pair anonymously with one other person and run the same product side by side. Metric deltas only. No photo, no name.

Niacinamide serum · 21 daysIllustrative sample
You · hydration
+5.8
Your duo · hydration
+0.4

Supported for you, inside the noise floor for them. Same bottle, different skin.

Two men about thirty side by side at a travertine counter on a sunlit terrace above the sea, one reading his phone, the other looking at an unlabelled amber bottle.

p. 13 · Subscriptions

Free to measure. Pro to see every verdict.

The annual trial runs 14 days on purpose. It is how long the first verdict takes, so you see what you are paying for before you pay.

Free

$0

No account, no card, no expiry.

  • Guided baseline with your personal noise floor
  • One progress check in, up to three products
  • Daily routine logging and streaks
  • Derm Duo, in full

Pro

$69.99 a year

or $9.99 monthly. Cancel any time in Apple ID settings.

14-day free trial
  • Every claim verdict, with its uncertainty interval
  • Unlimited products and weekly check ins
  • Full history and metric timeline
  • Environmental context on every reading

p. 14 · The interview

Straight answers.

How can a phone camera be accurate enough?

On its own it isn’t, and that is the honest answer. Readings become comparable because capture conditions are locked and recorded, your own replicate frames define how much the measurement wobbles, and no change smaller than that wobble is ever called a result. DermProof measures change in your own readings over time; it does not claim an absolute clinical value for your skin.

Do I need special lighting or a stand?

No hardware at all. Check in at the same spot, in the same light, each time, and skip alcohol on check-in days if you can. The app locks and records the camera settings, so ordinary variation is measured rather than mistaken for your skin changing.

Why 14 days before a verdict?

Skin changes slowly and shorter windows mostly measure noise. Fourteen days is the minimum at which a hydration or texture trend can separate from your own variability, which is also why the annual free trial is exactly that long.

What is evidence strength?

A summary of how well your own data supports a claim: which way the metric moved, how big the move is relative to your noise floor, how many good captures back it, and how tight the trend is. It is not a probability that the product works, and it is not clinical certainty.

Do you recommend products?

No, and we don’t plan to. DermProof sells nothing, takes no affiliate revenue and has no opinion about what you should buy. That is what makes a “Not supported” result believable.

Do my photos really stay on the phone?

Yes. Photos and all pixel analysis stay on the device, and there is no DermProof account. The only things that can leave are anonymous, non-image rows you opt into: a claim result for pooled stats, a Duo pairing code, and coarse weather context. One tap deletes them.

Is this a medical device or a diagnosis?

No. DermProof measures visible change in tracked metrics and tells you whether a product’s claim held up in your own data. It does not diagnose, treat or screen for any condition. See a dermatologist for anything medical.

An East Asian woman in her early thirties in a white towelling robe sits at the edge of an infinity pool above the sea, face turned to the sun.

Back cover · Early access

Find out which half of your shelf is working.

DermProof opens on TestFlight this autumn. Leave an email and the invite reaches you before the App Store does.

Free to start · No account · Nothing uploaded