What is a serum?
Irmelind van Zyl 
You are not alone if you have no earthly idea what a serum is. Lets have a look at what is and why we should use it.
You are not alone if you have no earthly idea what a serum is. Maybe you are the proud owner of several serums in your cupboard, maybe you even collect them, but it’s not a particularly clear product on it’s surface.
Think of the contradictions:
It’s moisturizing, but you still use moisturizer? It can be oily, but it’s not necessarily a face oil. It can be watery, but is it an essence? It exfoliates, but it does not contain granules. So what the hell is it? And why does my skincare professional keep insisting I use it?
Skincare should never stress you out, so I did a bit of research, and compiled a cheat sheet for you to use.
What is serum?
A serum is a skincare product you can apply to your skin after cleansing but before moisturizing with the intent of delivering powerful ingredients directly into the skin. A serum is particularly suited to this task because it is made up of smaller molecules that can penetrate deeper into the skin and deliver a high concentration of active ingredients. This makes them a great tool for targeting specific skincare concerns, like wrinkles.
How often should I use my serum?
Well, this all depends on the serum and what the benefits are. Generally the skincare professional will give you an indication of how and when to use it. Alternatively read the label, but once a day should be sufficient to derive the benefits from it.
What’s the difference between serum and face oil or a moisturizer?
This is a good question. Traditional serums are water-based. Though, as face oils become more popular and the trend grows, more oils are marketed as ‘serums.’ You have the water-based serums and the oil-based serums, both for different reasons and effects.
Water-based serums go under your day or night cream and they are important. They nourish the underlying layers of the skin because their molecules are very small so it penetrates deeper.
The oil-based serums also generally go under a moisturizer, because of their benefits, but their molecular structure tends to be bigger, so not that much penetration, more a question of nourishing the skin and its top layers.
Serums can be filled with lots of of moisturizing ingredients, like for instance hyaluronic acid and ceramides to help the skin retain moisture. Remember that a moisturized skin is better able to protect itself and does not age as quickly. But, that doesn’t make them moisturizers in the traditional sense. Face lotions and creams tends to be richer and create a barrier on top of the skin to keep all that good stuff in.
What about the shelf life of a serum?
Certain potent ingredients often found in serums can become quite unstable once they come in contact with air. Most serums tend not to contain a lot of preservatives to help protect the ingredients, so a serums tends to be something that should be used up as soon as possible and not kept on the shelve.
Ascorbic acid (vitamin C), for instance, can oxidize and lose efficacy over time. Thanks to science however, modified versions of the ingredient (that are water-soluble for instance) last longer so they can do your skin more good. The best rule of thumb is to store your serum in a cool, dry place and use it up within the period indicated by the product manufacturer or your skincare professional.
How do you know if a serum is serum right for your skin?
Most skins can do with an occasional boost in the form of a serum at least once or twice a year in the case of a younger skin or constantly if you are ageing.
If you’re…
Acne-prone:
- Look for retinol (vit A.) which reduces inflammation and help with exfoliates.
- Zinc, which soothes irritation, regulates oil production and
- Salicylic acid, which helps to unclog pores.
Dry skin:
- Look for ingredients like vitamin E, which is an antioxidant and protects cells from oxidative damage and nourishes the skin
- Niacinamide to improve skin elasticity and increase ceramide levels in skin
- Glycolic acid, gently exfoliates and lightens discoloration and
- hyaluronic acid, whihc is able to hold 1000 times its weight in water and therefore retains moisture
Feeling dull:
- Look for antioxidants like green tea extract, resveratrol and ferulic acid, because they combat free radicals, increase effectiveness of sunscreen by day, and promote cellular repair and healing by night
Just remember, because serums are usually super potent, more is not always better. Be careful before piling it on. Powerful ingredients can irritate and already sensitive or irritated skin.