Salicylic Acid and Sulfur (Topical Route)

Salicylic acid and sulfur combination is used in the treatment of certain skin and scalp disorders, including acne and dandruff.


Salicylic acid and sulfur combination in topical form is used to treat patients who suffer from mild skin and scalp disorders, such as dandruff, acne, and seborrheic dermatitis.

Sulfer and salicylic acid belong to a group of chemicals called keratolytic agents. They work in combination by causing the patient’s skin to shed all the dead cells from the upper dermal layer. The medication increases the quantity of moisture contained in the skin and dissolves the protein that causes the cells to stick together. The overall effect makes shedding the dead cells easier, softens the upper dermis, and reduces dryness and scaling. Salicylic acid actually belongs to the same group of drugs as aspirin.

The medication comes in various forms including lotion, liquid, soap, cream, bar, shampoo, and ointment. You can buy salicylic acid and sulfur combination without a doctor’s prescription, over-the-counter at your local pharmacy or drug store.

In the US, salicylic acid and sulfur combination goes by the brand name, SAStid. In Canada, it is sold as Night Cast R and Fostex Cream.

Conditions Treated

  • Acne
  • Dandruff
  • Seborrheic dermatitis
  • Other skin and scalp conditions

Type of Medicine

  • Soap
  • Shampoo
  • Ointment
  • Lotion
  • Liquid
  • Cream
  • Bar

Side Effects

Some medicines can cause side effects, as well as providing benefits to the patient. Not all of these effects may take place, but you may need to talk to your doctor if you notice anything unexpected or unpleasant after you start using salicylic acid and sulfur combination. Sometimes any unwanted effects will disappear after a couple of days, without the need for further medical assistance. However, if these effects persist, you should speak to your GP about them.

Salicylic acid and sulfur combination is generally very safe to use and has few reported side effects. However, a few patients do report reddening, burning, or peeling of the skin or scalp around the treatment area. If you experience these effects, stop using the medication immediately and refer to your doctor for advice.

In extremely rare cases, a very serious allergic reaction called anaphylaxis may occur. Any of the following symptoms could mean that you are suffering from anaphylaxis, and you should call 911 immediately:

  • Rash
  • Swelling and itching of the tongue, inside of the mouth, and throat
  • Breathing difficulties
  • Severe dizziness

The side effects mentioned here are not necessarily the only ones that this drug can cause. If you notice any other unexpected effects, have a chat with your GP.


You should only use salicylic acid and sulfur combination as directed. Do not use any more or less of it than is recommended on the product packaging, unless you have been instructed otherwise by your GP.

When you have used the medication, wash your hands immediately to remove any residue.

Avoid getting salicylic acid and sulfur combination in your eyes. If you do, flush away the chemical with clean, warm water. Do not rub your eyes or put any form of eye drops in them.

Using the skin cleansing lotion

  • Wet the skin over the affected area, and then use a wet sponge or your fingers to work the lotion into a lather by gently rubbing it in. Rinse away the lather completely, and pat the skin dry.

Using the bar or shampoo

  • Wet your scalp and hair with tepid water. Apply a sufficient quantity of the product to create a lather, and then rub it into your scalp. Keep massaging the lather into your scalp for a few minutes, and then leave it to work on your scalp for about five minutes. Rinse away the lather, and then repeat the process, rinsing thoroughly afterward.

Using the bar as a soap

  • Wet the skin over the affected area. Wash all affected areas with the bar. Rinse away the soap completely, and then pat the skin dry.

The amount of salicylic acid and sulfur combination that you use will vary between patients. You should keep to the instructions on the medication packaging or follow your doctor’s directions. Do not change your dose, unless you are told to do so by your GP.

The dose you are told to use will vary, depending on the potency and nature of the formulation that you are given to use. In addition, the frequency and duration of use will vary, depending on the condition for which you are being treated.

The following dosage rates are just based on the average for this type of medication. If your prescribed dose is different, do not change it, unless your doctor tells you to.

For oily skin or acne (bar)

  • Adults and children: Apply the medication to affected areas twice or three times daily.

For oily skin or acne (cleansing lotion)

  • Adults and children: Apply the medication to wet skin around affected areas once or three times daily. Massage the lather into your skin for a minute or so, and then rinse it away.

For seborrheic dermatitis and dandruff (shampoo and bar)

  • Adults and children: Apply the medication to your scalp once daily, twice a week or as instructed by your GP. You may repeat the treatment more frequently if necessary.

If you omit a treatment with the medication, try to apply it immediately. However, your next treatment is almost due, miss out the omitted dose and resume your usual treatment schedule. Do not double the treatment, as doing so could cause side effects.


There are some groups of drugs that should never be used together, as to do so could cause an interaction. However, in certain cases, your GP may deem it necessary to use one or more medications simultaneously, even though this may cause an interaction to take place. In such cases, it is common for the treating physician to change the dose or treatment frequency of one or more of the medicines. You may also be given advice on how to prevent or manage any interactions that do occur during your course of treatment.

Using Ketorolac with salicylic acid and sulfur combination is not recommended. If you are already taking this drug, your doctor may decide to change it or may elect not to treat you with salicylic acid and sulfur combination.

It is not usually recommended to use salicylic acid and sulfur combination with any of the following drugs, although it may be necessary in some cases. If you are told to use both medications together, your GP may adjust the dose or frequency of use of one or both drugs:

  • Abciximab
  • Xipamide
  • Vortioxetine
  • Vorapaxar
  • Vilazodone
  • Venlafaxine
  • Valdecoxib
  • Trimipramine
  • Trichlormethiazide
  • Triamterene
  • Treprostinil
  • Torsemide
  • Tolmetin
  • Tolfenamic Acid
  • Tirofiban
  • Tinzaparin
  • Ticlopidine
  • Ticagrelor
  • Tiaprofenic Acid
  • Tianeptine
  • Tenoxicam
  • Tacrolimus
  • Sulindac
  • Spironolactone
  • Sibutramine
  • Sertraline
  • Rofecoxib
  • Reviparin
  • Reboxetine
  • Protriptyline
  • Proquazone
  • Propyphenazone
  • Proglumetacin
  • Prednisone
  • Prednisolone
  • Prasugrel
  • Pralatrexate
  • Polythiazide
  • Piroxicam
  • Piketoprofen
  • Phenylbutazone
  • Pentoxifylline
  • Pentosan Polysulfate Sodium
  • Pemetrexed
  • Paroxetine
  • Parnaparin
  • Parecoxib
  • Paramethasone
  • Oxyphenbutazone
  • Oxaprozin
  • Opipramol
  • Nortriptyline
  • Nimesulide Beta Cyclodextrin
  • Nimesulide
  • Niflumic Acid
  • Nepafenac
  • Nefazodone
  • Naproxen
  • Nadroparin
  • Nabumetone
  • Morniflumate
  • Milnacipran
  • Metolazone
  • Methylprednisolone
  • Methyclothiazide
  • Methotrexate
  • Meloxicam
  • Melitracen
  • Mefenamic Acid
  • Meclofenamate
  • Meadowsweet
  • Lumiracoxib
  • Loxoprofen
  • Lornoxicam
  • Lofepramine
  • Lithium
  • Levomilnacipran
  • Ketoprofen
  • Indomethacin
  • Indapamide
  • Imipramine
  • Iloprost
  • Ibuprofen
  • Hydroflumethiazide
  • Hydrocortisone
  • Hydrochlorothiazide
  • Gossypol
  • Ginkgo
  • Furosemide
  • Fluvoxamine
  • Flurbiprofen
  • Fluoxetine
  • Fluocortolone
  • Flufenamic Acid
  • Floctafenine
  • Feverfew
  • Feprazone
  • Fepradinol
  • Fenoprofen
  • Felbinac
  • Etoricoxib
  • Etofenamate
  • Etodolac
  • Ethacrynic Acid
  • Escitalopram
  • Eptifibatide
  • Epoprostenol
  • Eplerenone
  • Enoxaparin
  • Edoxaban
  • Duloxetine
  • Droxicam
  • Doxepin
  • Dothiepin
  • Dipyrone
  • Dipyridamole
  • Digoxin
  • Diclofenac
  • Dibenzepin
  • Diazoxide
  • Dexketoprofen
  • Dexibuprofen
  • Dexamethasone
  • Desvenlafaxine
  • Desipramine
  • Deflazacort
  • Danaparoid
  • Dalteparin
  • Cyclosporine
  • Cyclopenthiazide
  • Cortisone
  • Clopidogrel
  • Clopamide
  • Clonixin
  • Clomipramine
  • Citalopram
  • Cilostazol
  • Chlorthalidone
  • Chlorothiazide
  • Certoparin
  • Celecoxib
  • Cangrelor
  • Bumetanide
  • Bufexamac
  • Budesonide
  • Bromfenac
  • Betamethasone
  • Beta Glucan
  • Benzthiazide
  • Bendroflumethiazide
  • Bemiparin
  • Aspirin
  • Ardeparin
  • Anagrelide
  • Amtolmetin Guacil
  • Amoxapine
  • Amitriptylinoxide
  • Amitriptyline
  • Amineptine
  • Amiloride
  • Acemetacin
  • Aceclofenac

To use salicylic acid and sulfur combination with any of the following drugs could present an increased likelihood that you will suffer from some side effects. However, using both medications together could be the best course of treatment in your case. If you are prescribed both medicines, your doctor might decide to change how often and for how long you use one or both of the drugs.

  • Zofenopril
  • Warfarin
  • Valsartan
  • Trandolapril
  • Timolol
  • Temocapril
  • Telmisartan
  • Tamarind
  • Spirapril
  • Sotalol
  • Ramipril
  • Quinapril
  • Propranolol
  • Probenecid
  • Practolol
  • Pindolol
  • Phenprocoumon
  • Phenindione
  • Perindopril
  • Pentopril
  • Penbutolol
  • Oxprenolol
  • Olmesartan
  • Nebivolol
  • Nadolol
  • Moexipril
  • Metoprolol
  • Metipranolol
  • Losartan
  • Lisinopril
  • Levobunolol
  • Labetalol
  • Irbesartan
  • Imidapril
  • Fosinopril
  • Esmolol
  • Eprosartan
  • Enalaprilat
  • Enalapril
  • Dicumarol
  • Delapril
  • Cilazapril
  • Celiprolol
  • Carvedilol
  • Carteolol
  • Captopril
  • Candesartan
  • Bisoprolol
  • Betaxolol
  • Benazepril
  • Azilsartan Medoxomil
  • Azilsartan
  • Atenolol
  • Anisindione
  • Alacepril
  • Acenocoumarol
  • Acebutolol

In addition to other medications that should not be used with salicylic acid and sulfur combination, some foodstuffs, alcohol, and tobacco should not be used or consumed, as they may cause an interaction to take place. Your doctor will discuss this with you if appropriate.


When you are using sulfur and salicylic acid combination, you should avoid using any of the following preparations on the same application site as this drug, unless your GP instructs you to do so:

  • Cleansers or soaps that have abrasive properties
  • Preparations that contain alcohol
  • Other acne treatments or treatments that contain resorcinol, benzoyl peroxide, or tretinoin, as these substances can cause the skin to peel
  • Soaps or cosmetics that may dehydrate the skin
  • Face packs that may dehydrate the skin or encourage peeling
  • Medicated cosmetics
  • Any other form of topical skin medication

The use of any of the aforementioned products on the same application site as salicylic acid and sulfur combination could cause severe inflammation and irritation of your skin.

You should not use any topical preparations that contain mercury on the same treatment area as that where salicylic acid and sulfur combination is being applied. To do so could cause skin irritation, black staining of the skin, or a foul odor. If you are unsure about this, ask your GP for more information.

Salicylic acid contains aspirin. Do not take large doses of aspirin or other salicylates, such as diflunisal, during your course of treatment with salicylic acid and sulfur combination. To do so could put you at risk of overdosing.

If you are aware of any allergic reactions or unusual effects that you have experienced while using this medication or any other drugs, you must tell your doctor. You should also tell your GP if you are allergic to particular food groups, food colorings, preservative, or animal derivatives. Tell your doctor if you are already using over-the-counter drugs (especially aspirin), vitamin supplements, or herbal remedies.

Young children may be at risk of side effects or overdose when being treated with salicylic acid and sulfur combination, because of the increased absorption of the drug through their skin. Do not use salicylic acid and sulfur combination on large areas of the skin or for long periods in small children and infants.

There is no evidence to suggest that salicylic acid and sulfur combination presents a risk to an unborn baby. However, if you are pregnant or you think that you may become pregnant while you are using this medication, check with your doctor.

It is not known whether salicylic acid and sulfur combination passes into breast milk. If you are breastfeeding, you should discuss the safety of continuing to do so during your course of treatment with this medication.


Salicylic acid and sulfur combination preparations should be kept in closed containers and at room temperature. Do not place your medication near to a heat source or in direct sunlight. Do not refrigerate or freeze the product.

Keep salicylic acid and sulfur combination medicines out of reach of pets and children.

Once the medication is open or has passed its use-by date, you should dispose of it safely and do not use it.


Salicylic acid and sulfur combination in its various topical forms is used in the treatment of people with mild skin and scalp disorders, including dandruff, acne, and seborrheic dermatitis.

The medication is available without a prescription, although it is advisable to discuss its use with your doctor beforehand, as there are a large number of drugs that can cause an interaction when used in combination with it.


Last Reviewed:
January 31, 2018
Last Updated:
January 27, 2018