Selsun Blue 2.5% Extra Strength Antidandruff Shampoo
A strong selenium sulfide shampoo with mixed results and frequent complaints about dryness and smell.
The short version
- Adults with persistent dandruff who want the maker's extra strength option
- People happy to use a medicated shampoo twice a week and a regular shampoo in between
- You are pregnant or breastfeeding; the maker does not recommend it
- You coloured or permed your hair in the last 48 hours
- You are allergic to selenium sulfide
- You want a mild daily shampoo
What owners like
- Some users report less itching and flaking within a few weeks
- Some fold it into a rotation with other shampoos for long term use
Common complaints
- Results are mixed; some users see no change or the flaking returns
- Dries out hair, leaving it brittle or rough for days
- Strong smell that lingers after rinsing
- Some users report breakage, shedding or a burning scalp
Based on The maker's Canadian product page, a Canadian pharmacy listing, and WebMD's selenium sulfide drug page and user review themes.
Research scores
Scored from the maker's specs and what owners report. Drew's own notes and photos will refine these.
Ownership
- Jun 2025
First bought.
Drew's hands-on notes for this product are on the way. Long-term updates will be added to this timeline.
What it does
A medicated shampoo with 2.5% selenium sulfide; the 200 mL pro-vitamin B5 bottle has given way to a 250 mL version with vitamin B3 on the maker's Canadian site, and this page covers both.
- Label directions for the scalp: lather into wet hair, leave 2 to 3 minutes, rinse, repeat
- The maker says to use it twice a week for two weeks, then as needed, rather than daily
- Separate label directions cover tinea versicolor on the body
- The maker describes the current formula as pH balanced and not tested on animals
- The same maker sells other versions such as Itchy Dry Scalp, 2-in-1 and Normal-Oily Hair
A fit for adults who want the highest strength selenium sulfide shampoo the maker sells in Canada and are willing to follow the label's twice a week routine. The trade-off is comfort: users often report dry hair and a smell that lingers, results are mixed, and the label carries more warnings than an everyday shampoo.
How it compares
Specs
- Active ingredient
- Selenium sulfide 2.5%
- Size
- 200 mL (older pro-vitamin B5 version); 250 mL (current version on the maker's site)
- Added vitamin
- Pro-vitamin B5 (panthenol) in the older version; vitamin B3 (niacinamide) in the current version
- Maker-stated uses
- Dandruff, seborrhea and tinea versicolor
- Free from (current version)
- Parabens, SLS, phthalates and phosphates, per the maker
- Colour and scent
- Light orange, contains fragrance
Worth knowing
- For external use only. The maker says to avoid the eyes, as contact can cause a severe reaction.
- Do not use if allergic to selenium sulfide or any ingredient, or on broken or infected skin.
- Wait 48 hours after hair colouring or permanent waving.
- The maker does not recommend it during pregnancy or breastfeeding.
- Keep out of reach of children.
Questions
How often should you use Selsun Blue 2.5%?
The maker's directions say twice a week for two weeks, then as needed. It is not meant for daily use.
How long do you leave Selsun Blue in?
The label says 2 to 3 minutes on the scalp before rinsing, then repeat.
Is the 200 mL pro-vitamin B5 version still made?
The maker's Canadian site now lists a 250 mL bottle with vitamin B3. The active ingredient is still 2.5% selenium sulfide.
Can you use Selsun Blue on coloured hair?
The maker says to wait 48 hours after colouring or perming before using it.
Sources
- Selsun Blue Canada: 2.5% Extra Strength Antidandruff Shampoo
- Well.ca: Selsun 2.5% (200 mL)
- Amazon.ca: Selsun Blue Anti-Dandruff Shampoo, 200 mL (product listing)
- WebMD: Selenium sulfide uses, side effects and warnings
- WebMD: Selenium sulfide user reviews
- Head & Shoulders: Clinical Strength Oil Control Dandruff Shampoo
- Costco: Nizoral Anti-Dandruff Shampoo with 1% Ketoconazole
- Selsun Blue Canada: Itchy Dry Scalp Antidandruff Shampoo
Researched 2026-10-01. We bought this product; our page is built from the maker's details and what owners report across reviews and forums. We never copy Amazon customer reviews.