Cryotherapy vs Photodynamic Therapy

Cryotherapy: Liquid nitrogen is sprayed or dabbed onto a spot to freeze and destroy it. It is a standard treatment for warts, precancerous sun spots and some harmless growths. It commonly leaves a pale mark that does not fully come back.

Photodynamic Therapy: A light-activated drug applied in the office, then switched on with a lamp or laser. It is the strongest non-drug option for inflammatory acne, and the downtime is a real week.

Reviewed by Dr. Schwarz, Board-Certified Dermatologist
Last updated: 10/22/2026

Editorial illustration for Cryotherapy, based on the entry’s treatment or equipment reference.

Editorial illustration for Photodynamic Therapy, based on the entry’s treatment or equipment reference.

Choose if Key differences What is it?What it treats Treatment areas Skin tones How it works Before your treatment Day of treatment After your treatment Risks Cost Questions Related

Choose Cryotherapy if…

Choose for quick removal of warts, sun-damage spots or harmless growths — accepting a possible pale mark.

A wart or rough sun spot
You want it done in one quick visit
A pale mark wouldn't bother you

Choose Photodynamic Therapy if…

Choose to treat a whole area of sun damage at once — or as a strong non-drug option for stubborn acne — with a real week of downtime.

Many precancerous patches on the face or scalp
You can stay out of light for 48 hours
You can take a week of redness

Alternatives, not combined

Can you have both?

Both treat actinic keratoses. Cryotherapy suits a few spots; photodynamic therapy treats a whole sun-damaged area. Sometimes thick spots are frozen before PDT.

Key differences

● Cryotherapy

● Photodynamic Therapy

DowntimeNone → 2+ weeks

1–2 weeks

3–7 days

PainMinimal → Needs anesthesia or sedation

Mild

Moderate

Results showImmediately → 3+ months

1–4 weeks

How long it lastsWeeks → Years or permanent

Years or permanent

1–2 years

Visits neededOne → Every few months

A short series (2–3)

Cost per visit$ → $$$$$

ReversibleYes, can be undone → No, permanent

No, permanent

What is it?

Cryotherapy

Photodynamic Therapy

What is it?

It freezes tissue.

Liquid nitrogen destroys selected tissue through freezing and thawing.

It treats diagnosed lesions.

It is used for benign or precancerous spots.

It leaves no specimen.

Nothing remains for microscopic examination.

Uncertain moles should not be frozen.

A diagnosis is needed first.

It pairs medicine with light.

A photosensitizing medicine is activated by a set light exposure.

It treats precancers.

It is used for actinic keratoses and some superficial lesions.

It differs from LED therapy.

It is not ordinary LED or UV treatment.

Light avoidance is needed after.

Sunscreen alone may not prevent activation.

What it treats

Evidence level

Cryotherapy

Photodynamic Therapy

Strong evidenceMost established uses

A rough, dome-shaped wart on the side of a finger on fair skin. The bump is pinkish with a thin red ring at its base, and several tiny black dots are clearly visible in the thickened surface.

Warts

A first-line treatment.

Actinic Keratosis

Clears precancers.

Two growths on the upper back on fair skin. One is a flat light tan patch and the other is a raised mid-brown growth with a rough waxy surface and a sharply defined edge.

Seborrheic Keratosis

Removes growths.

Actinic Keratosis

Clears 75–90% of spots.

Moderate evidenceSome supportive research

AI-generated educational illustration: A small soft hanging skin growth on light skin.

Skin Tags

Freezes small tags.

Basal Cell Carcinoma

Treats superficial types.

Limited evidenceEarly or small studies

—

Acne

Used for stubborn acne.

Little evidence

A raised, smooth, firm scar on the upper chest on light skin. It is shiny pink-red and hairless, and its edges spread well past the small mark it grew from.

Keloids

Injections work better.

—

Not effective

Melanoma

Needs excision.

Melanoma

Needs excision.

Can make it worse

—

Flat tan patches with soft irregular edges across the forehead and upper cheek of an adult with light skin, the surface completely smooth.

Melasma

Light can darken patches.

Treatment areas

The specific lesion, scar or affected patch determines the treatment site; there is no fixed body distribution.

Face; the selected area depends on the concern and treatment plan.

Skin tones

Skin tone

● Cryotherapy

● Photodynamic Therapy

Lighter skin

Some risk

A pale mark may not fully return.

Low risk

Redness and peeling.

Medium skin

Some risk

Pale or dark marks are more visible.

Some risk

Temporary darkening possible.

Deeper skin

Higher risk

Lasting pale patches are common; ask about alternatives.

Some risk

Dark marks are more likely; strict light avoidance helps.

How it works

Cryotherapy

Photodynamic Therapy

How it works

Cryotherapy mechanism diagram. A selected lesion is frozen: A clinician applies liquid nitrogen to the treatment area. Cold injures the tissue: A controlled freeze-thaw response damages the target. The treated area sheds and heals: A blister or crust may form; repeat treatment can be needed.

Photodynamic Therapy mechanism diagram. A photosensitizer is applied: The selected medicine accumulates in the prepared treatment area. Light activates the medicine: A matched light regimen produces reactive molecules. Selected cells are damaged: Inflammation and healing follow; treatment response varies.

Diagram explanation

A selected lesion is frozen: A clinician applies liquid nitrogen to the treatment area. Cold injures the tissue: A controlled freeze-thaw response damages the target. The treated area sheds and heals: A blister or crust may form; repeat treatment can be needed.

Schematic illustration. Technique and response vary. This explains a mechanism and does not specify treatment settings.

A photosensitizer is applied: The selected medicine accumulates in the prepared treatment area. Light activates the medicine: A matched light regimen produces reactive molecules. Selected cells are damaged: Inflammation and healing follow; treatment response varies.

Schematic illustration. Technique and response vary. This explains a mechanism and does not specify treatment settings.

Before your treatment

Cryotherapy

Photodynamic Therapy

2–4 weeks before

Not specified

2 weeks before: Sun and tanning: Avoid sun and tanning for 2 weeks.

Before you book: Time off: Clear several days, especially the 48 hours after, when you must stay out of sunlight and bright indoor light.

The week before

A few days before: Thick warts: Soaking and filing the wart with a pumice stone or emery board helps the freeze reach the wart, not the callus on top.

Ask your provider: Several spots: If more than one spot is planned, ask to start with one and see how the skin heals.

5 to 7 days before: Actives: Stop retinoids and exfoliating acids.

Day of treatment

Cryotherapy

Photodynamic Therapy

Arrival & prep

The spot is examined first — the most important part of the visit.

Photos, consent covering the off-label use and the downtime, and a medication review.

Treatment

Liquid nitrogen is sprayed or dabbed on until a white frozen halo covers the spot and a small margin.

A sun spot takes seconds; a wart takes longer and is usually thawed and frozen again the same visit. It burns and stings, peaking as the skin thaws, then aches for a few hours. Fingertips, toes, soles and ears are sorest. Brief and unpleasant, not severe.

Skin is cleaned and degreased, sometimes with microdermabrasion or an acetone wipe, so the drug soaks in evenly.

The solution goes on and you wait 20 minutes to 3 hours in a dim room. Then eye shields go on and you sit under a blue or red light for 8 to 20 minutes, or a laser or IPL is passed over. Stinging builds and peaks at the end; cold air helps.

Before you leave

Red, swollen and tender, sometimes blistering within the hour.

The least comfortable procedure on this list.

After your treatment

Cryotherapy

Photodynamic Therapy

First 24 hours

Days 1 to 3: A clear or blood-filled blister is expected, not a sign anything went wrong.

First 48 hours: Stay strictly out of sunlight and bright indoor light; daylight through a window can trigger a severe reaction.

Days 2–7

Days 4 to 14: The blister dries into a dark crust with the growth on top, and lifts off on its own over one to two weeks.

Days 4 to 10: Peeling and flaking, sometimes in sheets.

Weeks 2–4

Weeks 2 to 8: New skin is pink and delicate.

Weeks 1 to 2: An acne flare is common in the first week or two, before improvement starts.

Time to results

1–3 weeks

2–4 weeks

How long results last

Permanent for growths; warts may need repeats

Treated spots clear; new ones may form

Risks

A pale mark that is not filling back in
A dark mark
Numbness or tingling
A raised or thickened scar
Hair loss in the treated patch
Still not healed after 4 weeks
The growth is back or never went

Dark patches
Prolonged redness
A cold sore outbreak

Cost

Per session

Cosmetic prices vary a lot and are usually quoted per lesion or per visit, cheaper per spot when several are done at once.

In the US, PDT for acne generally costs about $400 to $1,500 per session, so a course commonly lands between $800 and $4,000.

Insurance

In the US, freezing warts and precancerous sun spots is billed as medical treatment, so you pay your copay or whatever the deductible has not covered.

Insurance does not cover PDT for acne, because the approved indication is precancerous sun damage.

Questions

Cryotherapy

Photodynamic Therapy

Individual Questions

Does freezing leave a white mark?

Often. Pigment cells die at milder cold than the growth, so most effective freezes take some color out. Some returns over months; a good part does not. The mark is usually a little wider than the spot and stands out far more on deeper skin tones — worth discussing before you agree.

Can a mole be frozen off?

No. Freezing destroys the tissue without a diagnosis, so a skin cancer can heal over at the surface while it keeps growing underneath. Anything pigmented, new or changing gets examined and sampled, and moles that need removing are cut out and sent to a laboratory. Same for at-home freezing and mole removal pens.

How much does it hurt?

A sharp burning sting for ten to thirty seconds during the freeze and the thaw, then an ache for a few hours. Fingers, toes, soles and ears are worst. Brief and genuinely unpleasant rather than severe, and ordinary painkillers are enough.

Is the blister normal, and should I pop it?

Normal, and it is how the treatment works — the skin separates and lifts the growth off with the blister roof. Leave it alone and cover it. If it is large, tense and painful, the clinic can drain it, which beats tearing the roof off yourself.

How many treatments will my wart need?

Usually several, every two to four weeks. Many clear over three to six treatments, some need more, and some never respond. Salicylic acid at home in between improves the odds. If nothing has changed after three or four sessions, ask about a different approach.

Are the drugstore freeze kits the same as what a doctor uses?

No. They use a propellant gas much warmer than liquid nitrogen and harder to aim, so they are weaker on thick and plantar warts. They can still blister and leave a pale mark. Not for the face, and never on a mole or an unexamined spot.

Is photodynamic therapy approved for acne?

Not in the US. It is FDA-approved for precancerous sun spots; using it for acne is off-label. That is legal and common, but it means no standard protocol and results that vary between clinics.

How bad is the downtime really?

Plan for 5 to 7 days of a visibly red, then swollen, then peeling face, with the worst in the first 48 hours. It is closer to a medium-depth peel than a laser facial.

Why do I have to stay out of the sun for 48 hours?

The drug is still in your skin, and sunlight — including through a car or office window — activates it and can cause a severe burn. This is the most important instruction of the treatment.

Does it cure acne?

No. Improvement typically lasts 6 to 12 months and repeat courses are often needed. It does not treat scars or existing brown marks.

Is it safe on deeper skin tones?

It can be done, but the risk of lasting dark patches is meaningfully higher, because the treatment works by causing strong inflammation. A shorter incubation, a lower light dose and an experienced provider make a large difference.

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