First, let's discuss pores. Your cannot shrink them, open them or close them. Whatever size they are, they are! All products can only reduce the appearance of large pores, not actually make them smaller. So, while you cannot physically make pores smaller, you can avoid making them look larger.
Pores can look larger because they get clogged with skin debris, makeup and dirt. Excessive oil can keep them filled with a layer of oil that accentuates their appearance. The growth of bacteria contributes to blackheads which makes pores appear larger. Exposure ot the sun can thicken skin cells around the edge of pores, making them appear larger. And, finally genetics determines your skin type and if you're born with oily, thicker skin your pores will probably be more noticeable.
There are things that can help reduce the appearance of large pores: washing your face, using exfoliating scrubs or cleansers, using pore strips, minimizing exposure to the sun and for women who wear makeup, using an oil-absorbing makeup and/or blotting sheets to keep excess oil under control. While all these things can help, the truth is there is not much that can be done about the size of your pores.
The main reason people buy pore (or nose) strips is because of blackheads. What is a blackhead? The technical term for a blackhead is is keratotic plug. They form when the opening of a hair follicle becomes clogged or plugged with dead skin cells and oil. This gunk gets oxidized by the air and appears black. The nose strips are designed to pull them out. But do they really work?
Nose strips remove top layers of dead skin cells and blackheads by using a very strong adhesive. The strips will extract anything on the surface of your nose which includes hair, dirt and oil. However, they will not prevent the buildup and blackheads from reoccurring.
The strip itself is made of a non-soluble woven substrate, that's the papery fabric-like body. On the underside there's a polymer that attaches to the oil plugs in your pores and a non-tacky resin to help the patch adhere to your nose.
It's essential for the resin to be wet so that it will stick to your skin. The water also activates the oil-grabbing polymer. Water provides a positive charge, which allows the polymers to bond to plugged pores, which have a negative charge. The activated polymers adhere to the outermost layer of skin, excess oil and hair that clogs pores. All this stuff on the urface level is pulled out when the strip is removed.
However, blackheads are a type of keratotic plug that lives deeper, below the surface of your skin. Thus, while the strips may remove the upper portions of sludge, they do not go deep enough to unclog hardened plugs, or blackheads, which are the reasons most people buy the nose strips for to begin with. The strips are a temporary cosmetic fix, nothing more.