Psoriasis
Clears moderate to severe plaques.
Methotrexate vs Mometasone
Methotrexate: An old, inexpensive tablet or injection for severe psoriasis and psoriatic arthritis. It is taken once a week, not daily, and it needs regular blood tests. Mometasone: A mid-strength prescription steroid applied once a day for eczema, psoriasis and other itchy rashes. Strong enough to settle a flare, measured enough for short courses on most of the body.
Which one is right for you?
Choose Methotrexate if…
Choose for severe psoriasis, especially with joint pain, as an inexpensive weekly treatment with regular blood tests.
- Psoriasis with psoriatic arthritis
- Cost matters and biologics aren't covered
- You can avoid alcohol and keep up blood tests
Choose Mometasone if…
Choose to settle an eczema or psoriasis flare on the body with a once-daily, mid-strength steroid.
- A flare on the arms, legs or trunk
- Hydrocortisone isn't strong enough
- You prefer once-daily use
Often combined
Can you take them together?
Mometasone is often used on remaining patches while taking methotrexate. They do not interact.
At a glance
● Methotrexate
● Mometasone
Type
Oral or injected immune suppressant
Mid-strength topical steroid (class 4)
What it does
Calms overactive immune cells and skin-cell growth
Calms inflammation and itch
Best for
Severe psoriasis and psoriatic arthritis
Eczema and mild psoriasis on the body
Prescription
Yes
Yes
Form
Tablet or injection
Cream, ointment or lotion
How often
Once a week — never daily
Once daily
Course length
Ongoing
2–4 weeks
Time to results
4–12 weeks
3–14 days
Main side effect
Nausea and tiredness the day after
Skin thinning with overuse
Blood tests
Required
None
Pregnancy
Never
Check with your clinician
Cost
Low; generic available
Low; generic available
What it treats
Compare uses by strength of evidence. Evidence level describes confidence in a benefit, not its size.
Evidence level
Methotrexate
Mometasone
Strong evidenceMost established uses
Eczema
Calms flares on the body.
Moderate evidenceSome supportive research
Psoriatic Arthritis
Reduces joint symptoms.
Eczema
An option for severe eczema.
Psoriasis
Reduces mild plaques.
Scalp Psoriasis
Lotion reduces scale.
Little evidence
Alopecia Areata
Mixed results in small studies.
—
Not effective
Acne
No role in acne.
—
Can make it worse
—
Rosacea
Steroids worsen rosacea.
Ringworm
Steroids let fungus spread.
How it works
Methotrexate
Diagram explanation and sources
Interferes with cell replication: Blocks folate-dependent processes used to make DNA. May increase adenosine signaling: This calming messenger can limit immune-cell activity. Reduces skin inflammation: Inflammatory activity and plaque buildup can decrease.
The psoriasis mechanism is not fully established. Folate antagonism affects replication, while low-dose anti-inflammatory actions include proposed adenosine pathways supported by experimental work; their precise clinical contributions are unresolved.
Mometasone
Diagram explanation and sources
Activates steroid receptors: Binds receptors inside skin and immune cells. Turns down inflammatory signals: Changes gene activity to reduce inflammatory messengers. Eases redness and itch: Swelling and irritation settle as inflammation falls.
Simplified glucocorticoid receptor-mediated effects in steroid-responsive skin inflammation. Full effects also involve other pathways. No claim of antimicrobial action or cure; formulation and potency affect clinical use.
How you take it
Treatment plan
This drug is taken once a week. Taking it every day can cause fatal bone marrow failure. Pick one day of the week, write it down, and keep to it.
Test dose: A single small dose, often 2.5 mg to 5 mg, with blood counts checked about a week later before going further. A safety check, not the treatment dose.
Starting dose: Commonly 7.5 mg to 15 mg once weekly, adjusted for age, weight, kidney function and other illnesses. Lower in older people and in reduced kidney function.
Going up: Small steps, usually 2.5 mg to 5 mg every few weeks with blood tests in between, until the psoriasis responds or side effects set the ceiling.
Usual dose: Most people settle between 15 mg and 25 mg once weekly. Above about 15 mg tablet absorption gets unreliable, a common point to switch to the injection.
Folic acid alongside it: It reduces nausea, mouth ulcers and blood count problems. Usually a daily dose on the days you are not taking methotrexate, or one larger weekly dose on a different day. It does not stop the drug working.
Total course: No fixed course. It continues as long as it works and blood tests stay normal, which for some people is years.
When to Apply: Once a day, a thin film on the rash only, not the skin around it. A fingertip length covers roughly two flat palms. Moisturizer can go on the same skin at other times.
How to Start: Once daily from day one until the skin is smooth and not itchy, usually a few days to two weeks. Under-using it is the commoner mistake. Then stop, or step down to twice a week if your doctor set that up.
If It Irritates: A short sting on cracked or raw skin is common and settles as the skin heals. Moisturizing twenty minutes before or after helps. Burning that worsens over days can mean infection, a reaction to the base, or the wrong diagnosis.
If It’s Not Working: Two weeks of daily use with no change means something else is going on — too little applied, a fungal or infected rash that steroids make worse, or a rash needing a stronger cream or a different drug. Do not keep going past that without a review.
When to take it
Once a week, on the same day every week. Choose a day you will remember and write it somewhere visible. Some people take the whole dose at once; some split it into two portions about twelve hours apart on the same day to reduce nausea. Do not spread it across different days unless you were told to.
Take tablets with water, and with food if they upset your stomach. An evening dose means the tiredness and mild nausea happen while you are asleep.
Folic acid goes on the other days, as prescribed. It is not a substitute for a missed methotrexate dose.
With the weekly injection, keep to the same day and rotate the site.
Not covered in this guide yet
If you miss a dose
Take it as soon as you remember if it is within about two days of your usual day. If longer, skip it and take the next on your usual day. Never take two weekly doses close together to catch up, and never take a daily dose to make up for a missed week.
If you have taken more than one weekly dose, or taken it several days in a row, contact a doctor or a poison center straight away. Do not wait to see how you feel. This overdose is treatable caught early and dangerous when it is not.
Not covered in this guide yet
Monitoring
Methotrexate is watched by blood test, and the schedule is not optional. The problems it causes are silent until they are advanced.
Before starting: Full blood count, liver tests, kidney function, and a pregnancy test where relevant. Hepatitis B, hepatitis C, HIV and tuberculosis screening is standard, because the drug damps the immune system. A chest x-ray if there is any history of lung disease.
Early on: Blood counts and liver tests within a week or two of starting, and again after each dose increase. This is when a sudden drop in blood counts would show.
Once stable: Full blood count, liver tests and kidney function every one to three months, depending on the dose and what else you take, for as long as you are on the drug.
The liver over the long term: Years of methotrexate can scar the liver, and the risk rises with total lifetime dose, heavy alcohol use, obesity, diabetes and fatty liver disease. Biopsy used to be the check; most clinics now use a blood marker of scarring and a scan of liver stiffness.
The lungs: A rare but serious lung inflammation can occur. A new dry cough, breathlessness or fever means being seen, not waiting for the next appointment.
What to report between tests: Mouth ulcers, unexplained bruising or bleeding, sore throat or fever, dark urine, yellowing of the eyes or skin, severe nausea, any new cough or breathlessness.
No blood tests for ordinary use. Monitoring is looking at the skin: is the treated area thinner or shinier than the skin beside it, are small veins showing, are there stretch marks in the folds or pus bumps around hair follicles.
The exception is large-area, long-term or covered use, and use in small children, where enough can be absorbed to affect the body’s own steroid production. Uncommon, and why a doctor sets an area and a time limit.
The checkpoint is a review at two to four weeks. Using it most weeks over months means the question is no longer the cream but what long-term treatment should be doing this job.
When you’ll see results
Approximate windows, not promises.
● Methotrexate
● Mometasone
First dose
First doseTaking it: Once a week, not daily, with folic acid on the other days. Nausea, tiredness or mouth soreness in the day or two after each dose is common early on; folic acid usually blunts it.
Weeks 1 to 2
Weeks 1 to 2Settling in: Nothing visible in the skin yet.
Weeks 4 to 8
Weeks 4 to 8Working: Plaques thin and spread less, thickness and scale first. Joint pain from psoriatic arthritis often improves in the same window, one reason it is chosen over a skin-only treatment.
About 3 months
About 3 monthsJudge it here: Substantial improvement is the realistic target.
Beyond 3 months
Beyond 3 monthsLong term: Where it suits, the result holds while the dose continues, with regular blood tests. Some stay on it for years.
Many months
Many monthsNails: Nail psoriasis can improve, but slowly. Nails always lag behind the skin.
First few minutes
First few minutesApplying it: A thin layer once a day, on the affected skin only.
Days 1 to 3
Days 1 to 3Itch first: Itch eases before the rash looks different. Normal, and not a reason to add more.
Days 3 to 14
Days 3 to 14Working: Redness fades, scale flattens, weeping stops. Most short courses finish here, and moisturizer keeps going after the steroid stops.
Weeks 2 to 4
Weeks 2 to 4Judge it here: If it is clear, stop or move to twice-weekly maintenance.
Weeks 2 to 6
Weeks 2 to 6Psoriasis plaques: Scale lifts and plaques flatten. Something else usually runs alongside, since steroids rarely hold psoriasis on their own.
Weeks to months
Weeks to monthsThickened, leathery patches: Skin rubbed and scratched for a long time takes longest, because the thickening itself has to reverse.
Beyond a few weeks of continuous use
Beyond a few weeks of continuous useThe risks: Thinning skin, visible small veins, stretch marks in folds, small pus bumps around hair follicles. Uncommon on short courses, and why long courses are planned rather than drifted into.
Side effects
Sorted by what to do about them.
Methotrexate
Mometasone
Common
Common
- Nausea or tiredness the day after the dose
- Mouth sores
- Mild hair thinning
Common
- Mild burning or itch
Tell your doctor
Tell your doctor
- Cough or breathlessness
- Fever, sore throat or unusual bruising
Tell your doctor
- Thin skin, stretch marks or easy bruising
- A rash that spreads (possible fungus)
Stop and get care
Stop and get care
- Taking it daily by mistake
- Yellowing skin or dark urine
Stop and get care
- Spreading rash with fever
Safety and who should avoid it
Pregnancy
Never
Both partners avoid conception during and for 3 months after.
Use care
Ask the doctor managing your pregnancy how much skin to treat.
Breastfeeding
Never
Not compatible.
Use care
Keep it off the nipple before a feed.
Children
Specialist only
Used in children with monitoring.
2 and older
Shorter courses.
Monitoring
Required
Blood counts, liver and kidney tests; every 3 months once stable.
None
Review at 2–4 weeks.
Key interactions
Check
Trimethoprim-sulfamethoxazole, NSAIDs, some antibiotics; limit alcohol.
None known
—
Other cautions
Avoid
Liver disease, heavy drinking, kidney disease, active infection.
Avoid
Face and folds for long periods; rosacea; ringworm.
Cost and getting it
Getting it and cost
Generic methotrexate tablets are among the least expensive systemic treatments in dermatology. Folic acid is cheap too.
The weekly auto-injector pens cost considerably more, and coverage usually requires showing that tablets caused nausea or did not work well enough. Plain injectable vials are cheaper than the pens.
The real cost is the monitoring, repeated blood tests and periodically a liver scan or blood marker. Usually covered, but they are appointments and not optional.
Insurers frequently require a trial of methotrexate before approving a biologic, one reason it is still so often the first systemic drug tried.
Generic mometasone is inexpensive and widely stocked, and the cream and ointment are on most low-cost generic lists. The Elocon brand costs considerably more for the same molecule.
The lotion and scalp solution usually cost more, and are sometimes the versions a plan will not cover. If cost is the issue, ask whether a different base at the same 0.1% would do the job.
When you stop
Comes back?
Psoriasis usually returns over months.
Eczema can flare again; twice-weekly maintenance helps.
Taper needed?
Usually not, but plan the next step first.
Step down to twice weekly rather than stopping abruptly after long use.
After the last dose
Wait at least 3 months before trying to conceive — applies to both partners.
Keep moisturizing.
Common questions
Methotrexate:How often do I take it?
Once a week, on the same day. Never daily. Daily dosing by mistake is the most dangerous error with this drug and it has been fatal. Get medical help the same day if it happens.
Methotrexate:Why do I also have to take folic acid?
Methotrexate blocks folate, and the mouth ulcers, nausea and low blood counts come from that. Folic acid on the other days restores enough folate to reduce them without stopping the treatment working.
Methotrexate:Do I really need all the blood tests?
Yes. Liver damage and falling blood counts cause no symptoms until they are advanced. The tests are the only early warning.
Methotrexate:Can I drink alcohol?
The concern is regular drinking, not a single glass, because alcohol and methotrexate both stress the liver. Agree an actual limit with your doctor.
Methotrexate:Can I take it if I want to have a baby?
No. It must be stopped well before trying to conceive, and the advice covers both partners. It causes miscarriage and serious birth defects. Ask your own doctor how far in advance.
Methotrexate:How long before I know if it is working?
Give it about three months. First changes often show at four to eight weeks, but three months on a tolerated dose is the fair point to judge.
Methotrexate:Is it chemotherapy?
It is chemotherapy at much higher doses. At psoriasis doses it acts as an immune-calming drug, and the experience is not comparable.
Mometasone:How long can I use it?
Two to four weeks on a defined area. Longer should be your doctor's decision, usually as twice-weekly maintenance.
Mometasone:Can I use it on my face?
Only if your doctor said so, and briefly. Facial skin absorbs far more and shows thinning first. Milder or non-steroid creams are usually chosen there.
Mometasone:Can I use moisturizer with it?
Yes, and you should — at a different time of day, so you are not diluting the steroid or spreading it beyond the rash.
Mometasone:Why has the rash come back?
The steroid treated the inflammation, not the cause. Expected in eczema and psoriasis, and why maintenance and steady moisturizing matter.
Mometasone:Is once a day really enough?
Yes. It was developed for once-daily use and the trials were done that way. Twice a day adds side effect risk without benefit.
Mometasone:What if it stings?
A short sting on broken skin is common and settles. Burning that builds over days, or a worsening rash, can mean infection or a reaction to the base.
Keep exploring.
Medication
Methotrexate
Medication
Mometasone
Compare
Hydrocortisone vs Methotrexate
Compare
Hydrocortisone vs Mometasone
Compare
Methotrexate vs Otezla
Compare
Mometasone vs Otezla
Compare
Calcipotriene vs Methotrexate
Compare
Calcipotriene vs Mometasone
Compare
Clobetasol vs Methotrexate
Compare
Clobetasol vs Mometasone
Compare
Cyclosporine vs Methotrexate
Compare