Blackheads are a type of acne. Normally, older skin cells work their way to the top surface of the skin and shed on a daily basis. In acne-prone skin, this process breaks down, and skin cells don't shed normally. (We still don't understand the exact reason for this.) Blackheads occur when dead skin, oil and bacteria clump in hair follicles (a.k.a. pores), rather than shedding normally. These clumps turn black as a result of oxidation after exposure to the air.
The best medications for treating blackheads are prescription retinoid creams like Retin-A. Over-the-counter medicine containing salicylic acid, retinol, and benzoyl peroxide, however, may be enough to treat mild blackheads/acne. There are a few tips for using these products: If you choose to use retinol, remember that you should apply it at night since sunlight may inactivate the product. And note that if you use a product containing benzoyl peroxide, it can bleach fabric. You should apply any product that you use to the entire affected area (don't just dab it on blackheads that you can see), in order to both treat obvious blackheads and those that are just starting but not yet visible.
If you choose to use pore strips, which attach to blackheads and may help remove them from the skin, know that they are not effective at preventing future blackheads from breaking out. Consult your doctor before using pore strips in combination with prescription creams, as they can cause skin irritation.
Be patient--it takes several months to see good results. Don't delay seeing a dermatologist, however, if you have acne that's leaving scars, as it could permanently damage your skin.
This is actually why I'm HUGE on toner, where most of the time you might hear that it's a waste of money. Check out why here :
But if you keep getting them, try a 30% Salicylic peel from someone who does them (like a med spa) or cosmetic surgeon. It does not hurt and has no down time. And microdermabrasion (or Vibarderm, which I prefer) might help.
And I agree with Daniella Ferri that toners are important. They act as a key to open the lock of the cell membrane, and allow skin care products to penetrate better.
If you want a good skin care routine for acne, Bare Skin has two (www.bareskincare.com), which is my company.
How I manage mine is I take baking soda and some water (that's it, nothing else) and I apply the mixture all over my face. Then I take a toothbrush and gently scrub my nose and chin for a few seconds. Leave it on for up to 5 minutes, then rinse thoroughly. This process can be repeated up to 3x a week on every second day. In about 2 weeks you should notice that your blackheads are less significant