Skin 101: Interactive Skin Anatomy

IPL Lab School · Skin 101

Your skin, layer by layer

Every treatment we offer works at a precise depth. Tap a layer or a numbered point on the plate to see what lives there, what can go wrong, and which treatment is built to reach it — the same map our students learn from.

3 layers · epidermis · dermis · hypodermis8 structures · to explore15+ treatments · mapped to depth
Interactive plate

Tap a point. See what we treat there.

Use the layer buttons to isolate one layer, or the numbered points for a close-up. Keyboard: Tab to a point, Enter to open.

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Start here

Three layers, one living organ

Skin is the body’s largest organ. The epidermis is the thin shield you see; the dermis underneath holds collagen, elastin, follicles, glands and vessels; the hypodermis is the cushion of fat below. Lasers, IPL, needles and radiofrequency are each tuned to a target and a depth — that is the whole art of choosing the right treatment.

Tap any numbered point to begin.

1 · Epidermis — 0.1 mm

Epidermis & skin barrier

What happens here

Five cell layers, about 0.1 mm thick, renew every 28–40 days. Keratinocytes rise from the base, flatten and form the stratum corneum — the waterproof brick-and-mortar barrier that keeps water in and irritants out.

What can go wrong

  • Dullness and rough texture when dead cells pile up
  • Dehydration and sensitivity when the barrier is damaged
  • Enlarged pores and congestion

What reaches it at IPL Lab

2 · Epidermis — 0.1 mm

Melanocytes & pigment

What happens here

Melanocytes sit at the base of the epidermis and hand melanin to surrounding cells. Melanin is your natural sunscreen and the reason skin tones differ — and the reason laser settings must respect your Fitzpatrick type.

What can go wrong

  • Sun spots and post-inflammatory marks after acne
  • Melasma: hormone- and heat-triggered patches
  • Uneven tone and intimate-zone darkening

What reaches it at IPL Lab

3 · Dermis — 1 to 4 mm

Hair follicle & bulb

What happens here

The follicle is a tunnel through the dermis; the bulb at its base makes the hair. Its melanin absorbs laser light, converts it to heat and disables the growth cells — which only works while the hair is in its active growth phase, hence multiple sessions.

What can go wrong

  • Unwanted hair and ingrown hairs
  • Folliculitis and razor bumps
  • Thinning hair on the scalp (the same follicle, the opposite goal)

What reaches it at IPL Lab

4 · Dermis — 1 to 4 mm

Sebaceous gland

What happens here

Attached to each follicle, the sebaceous gland produces sebum that waterproofs hair and skin. Hormones control its output.

What can go wrong

  • Oily skin and blackheads when sebum thickens
  • Active acne when a blocked pore becomes inflamed
  • Post-acne scars once inflammation damages the dermis

What reaches it at IPL Lab

5 · Dermis — 1 to 4 mm

Collagen & elastin mesh

What happens here

Fibroblasts weave collagen (strength) and elastin (recoil) into the dermis. From the mid-twenties we lose roughly 1% of collagen a year; sun and smoking accelerate it. Controlled micro-injury signals fibroblasts to rebuild.

What can go wrong

  • Fine lines, deeper wrinkles and sagging
  • Acne scars and stretch marks (broken mesh)
  • Loss of firmness in the jawline and neck

What reaches it at IPL Lab

6 · Dermis — 1 to 4 mm

Blood vessels

What happens here

Capillary loops rise into the papillae to feed the epidermis, which has no vessels of its own. They flush with heat, emotion and inflammation and carry nutrients to healing tissue.

What can go wrong

  • Persistent redness and visible capillaries
  • Rosacea flare-ups
  • Small vascular lesions and cherry angiomas

What reaches it at IPL Lab

7 · Dermis — 1 to 4 mm

Sweat gland

What happens here

Coiled deep in the dermis, eccrine glands cool the body through a duct that opens at the surface. They are not a laser target — but they explain why skin must be clean and cool before treatment.

What can go wrong

  • Heat rash and irritation after friction
  • Odour and congestion in folds
  • Post-treatment sensitivity if skin is overheated

What reaches it at IPL Lab

8 · Hypodermis — fat & support

Hypodermis — fat & support

What happens here

Lobules of fat held in a web of fibrous septa: insulation, shock absorption and the volume that keeps a face looking youthful. Lymph vessels run through it carrying fluid and waste.

What can go wrong

  • Cellulite: fat pushing between tight septa
  • Fluid retention and heaviness
  • Loss of tone when the muscle beneath weakens

What reaches it at IPL Lab

For students & curious clients

Three facts worth remembering

Depth decides the device

A peel works on the top 0.1 mm; IPL and lasers aim at pigment and follicles; needles and RF rebuild the dermis at 0.5–3.5 mm; EMS reaches the muscle. Matching target to depth is the first thing we check in your free consultation.

Skin tone is a parameter, not a limit

Darker skin carries more melanin everywhere, so wavelengths and energy are chosen to protect the epidermis (Nd:YAG for hair, PICO for pigment). The Fitzpatrick scale guides every setting.

Results follow the cycle

Hair grows in phases, collagen takes 4–12 weeks to remodel, the epidermis renews monthly. That is why packages of 4–8 sessions outperform single visits.

Prefer a scan? Our AI skin analysis maps pigment, hydration and texture in minutes.

IPL Lab School · Skin 101

Skin 101 — quick questions

How deep do lasers go into the skin?
It depends on the wavelength. Laser hair removal (diode, alexandrite, Nd:YAG) targets the follicle bulb 2–4 mm down; PICO laser targets pigment in the epidermis and upper dermis; fractional and RF devices create controlled columns of heat in the dermis. The epidermis is always protected by cooling.
What is the Fitzpatrick scale?
A 1–6 scale describing how skin reacts to sun, from very fair (I) to deeply pigmented (VI). It tells us how much melanin the epidermis holds and therefore which wavelength and energy are safe. We assess it at every consultation.
Why does collagen matter so much?
Collagen gives skin its strength and structure. Its slow loss is what we perceive as ageing. Microneedling, RF microneedling and skin boosters all work by prompting fibroblasts to produce new collagen over several weeks.
Can I learn this in depth at IPL Lab?
Yes — our esthetician school teaches skin anatomy, laser physics and hands-on protocols in English and French. See the School menu for courses.

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