Why your skin may appear worse when you first start a new product: I get a lot of emails with different variations of this question, generally saying "I have just started using XYZ product, it does not seem to be working for my skin. My skin has become (insert symptom, including dehydrated, oily, rough, dull, broken out)." I am very sympathetic to the difficult phase of when one tries a new product, so I would like to share the answer with all of you:
Your skin may appear worse because you have stopped using a product that has been working for you, and started a new one whose benefits has yet to kick in. I realize that many products promise permanent results, but the fact is, the results you receive from most beauty products begin to diminish as your use of the product ceases (with anti-aging products being an exception). However, keep in mind that if you experience worse skin, the symptoms should intensify during the first few days of trying a new product, rather than popping up the very day of trying a new product (with the exception of acne in reactive skins). For example, skin may become rougher and duller because your previous skincare products contains acids or other forms of chemical exfoliants, but it will happen in the span of around 3 days to a week.
Cleansers: If all you were expecting from a cleanser is to get your skin clean, you can expect the cleanser to work right away if it is going to work. However, if you are expecting anti-aging or acne-reduction benefits from your cleanser, please follow the guidelines below for that specific category.
Exfoliants: You should see softer and more glowy skin right away. However, full benefits should occur after half a month to a month of consistently using the product. If your skin appeared to be red and irritated (especially from a chemical exfoliant), your skin may become more used to an exfoliant after a period of use (ranging from a week to as long as 6 months). However, the most discomfort you should experience is flakiness or a burning sensation. Anything more than that would mean that you are allergic to the product, and therefore, you should discontinue use.
Moisturizers: If all you were expecting from a moisturizer is higher levels of hydration, you should see some benefits right away or several hours after application, with full benefits following after around 1.5 months of use. If you want brightening, anti-acne, or anti-aging, please follow the guidelines below for that specific category.
Anti-Aging Products: Anti-aging serums are an entirely different matter. By anti-aging, we mean age-prevention, which category generally consists of antioxidants and sunscreen/sunblocks. You are not supposed to see a lot of results from anti-aging serums because their effects are meant to be seen in the future. Therefore, unfortunately, you have to be very very careful in choosing products in this category, because you cannot use your skin's reaction as a guide to how well the product is functioning. I will do two articles on antioxidants, and sunscreen filters in the near future. However, some people do see some benefits from anti-aging products, such as plumper skin, or most frequently more radiant skin. This is because some antioxidants can repair some damages done to your skin in a very short period of time prior to using them.
Anti-Acne Products: Anti-Acne products are by far the most tricky, probably because acne is a tricky condition by itself. Many times, you may see your skin become worse before it gets better in this category of products, because some anti-acne products may bring to surface all the pimples that are forming deep in your skin, this is often called "surging". This type of products may take from 1 day to 6 months to work. However, you should be able to see a lessening of "bumps" on the skin, otherwise known as clogged pores.
Skin Plumping Products: This really varies by the type of product. For some products, you can see results from the first day, and for others, you can see results after a few months. It is best to ask the person you are buying the products from if they are the "authorized sellers". However, it should take at least 1.5 months for full benefits to develop for this type of products. I must also admit that skin-plumping products is not my "area of expertise", so I cannot go deeper into this type of products.
Skin Tone Improvement Products: This is also a tricky category. It is generally hard to see an effect after the first use, and many people become discouraged easily. I tend to allow for 1.5 months in order to see some slight slight improvements (unless the product promises otherwise), and if I see no benefits, I generally discontinue use unless I'm also using it for some other benefits.
Makeup: For makeup, of course, you should see benefits right away, unless you are expecting some skincare benefits from those makeup. "Makeup" benefits are defined as immediate benefits that can get washed away, and "skincare" benefits are defined as long-term improvements that will persist.
If you have sensitive or reactive skin: It is common to experience surge of pimples or redness when first using the product. However, be careful to avoid products that cause clogged pores, which generally show up as flesh colored bumps on your skin that is not inflamed, because clogged pores are not caused by the initial adjustment period. They are caused by heavy ingredients in the product incompatible with your skin type.
"It gets worse before it gets better products": There are a few categories of products that may make your skin get worse before it gets better. Generally anti-acne and exfoliants. One of the most famous/notable products in this category is Retin-A. It is a retinoid, and is used for acne, but it is also the only FDA-approved ingredients that reduces wrinkles. It may sound like a magical product, but in the beginning stages, many people experience acne, red, scaly, flaky, peeling skin.
Allergies: Do not mistake an allergic reaction to some products as the harmless initial reactions that will go away. You know your skin best, so you should be able to tell what types of allergic symptoms you are prone to. However, as a general rule of thumb, unless you are experiencing pimples, you should generally check whether you are allergic through googling or consulting your physician/dermatologist.