The realm of skincare is full of weird and wonderful ingredients. And everyday there is something new and popular to discover. Hemp and CBD oils or kakadu plum or prickly pear extract - or the huge rise in popularity of vitamin C and niacinamide.

But not all skincare ingredients are created equal. In fact, some are considered "active" and others are just ingredients. To find out the difference, we spoke to Terri Vinson BSc. Dip Form Chem, DipEd. ASCC, a leading Australian skin scientist. In addition to being extremely passionate about educating people on skincare, Terri is the formulator and managing director of Synergie Skin. Here, she explains the difference between and ingredient and an "active" ingredients and what to look out for.

What exactly is an active ingredient?

Active ingredients form the basis of a great skincare product and are responsible for delivering a visible change within your skin. Consider them your bathroom cabinet 'allstars'. Also known as cosmeceuticals, they are a hybrid of a cosmetic ingredient and a pharmaceutical ingredient with known biological actions when applied to the skin. This category of skincare is not classified as a scheduled drug, such as prescription vitamin A (Tretinoin) and can be sold in over the counter products.

Effective active ingredients have clinical data to support their activity on the skin function at a cellular level. There are thousands of actives available to formulators which can perform hundreds of actions on the skin including hydration, protection from free radical damage, repairing the barrier, stimulating collagen or reducing uneven skin tone. As a formulating scientist, I am continually monitoring ingredient choice and selecting the cleanest of both lab-created and naturally-derived ingredients.

How are these different from other skincare ingredients? What do they do?

Active ingredients are the powerhouse elements of the product, which are scientifically proven to have a positive impact on the skin. The rest of the product will contain supporting ingredients such as solvents, emollient oils, thickeners, preservatives, emulsifiers, and pH adjusters. These supporting ingredients are vital to creating an elegant, safe and stable product but are there as a support system, not as the heroes.

In contrast, 'passive' or 'fluffy' skincare products that are inexpensive and found on the shelf at your local supermarket will often feel nice on the skin and plump it up for a few hours but will make little change to your skin.

What are some kinds of active ingredients?

There are thousands of actives in the ever-evolving beauty market, and scientists are continually working on developing more effective cosmeceuticals. Some well-known active ingredients include:

• Niacinamide
• Vitamin C
• Lactic acid
• Salicylic acid
• Hyaluronic acid
• Numerous forms of peptides
• Hydroxy pinacolone retinoate (a new effective form of vitamin A)
• Retinol

Whether it be zits, dryness, uneven skin tone, oily skin, enlarged pores or wrinkles, there is an active ingredient created to target it.

Which ones, in particular, should we look out for? Are there any must-haves for our skincare routines?

Hands down, my must-have active is niacinamide. Also known as vitamin B3, it is considered the great multitasker of cosmeceuticals and is vital for the long term health of our skin cells. When formulated correctly, this cosmeceutical can reduce dryness, irritation, redness, hyperpigmentation, fine lines, and acne. Who doesn't need this little wonder active in their life?

Vitamin C is another favourite of mine. This powerhouse vitamin is the skin defender and fortifier. Antioxidants are an essential element of all skincare routines, and vitamin C protects our skin cells from damaging free radicals, particularly from UV light. As well as being a powerful antioxidant, vitamin C stimulates collagen for firmer more youthful skin and evens out skin tone for a more radiant complexion. Opt for a vitamin C in a form that is stable and gets to the target skin cells. My choice is pure L-ascorbic acid crystals mixed with water (at a 1:4 ratio) at the time of application, ensuring the the vitamin C remains highly active on the skin. L-ascorbic acid in serum form does not withstand being in a bottle with water present for more than a few days before it oxidises. The other form of vitamin C I like is ethyl ascorbic acid, as it is stable in serum form and highly active in the skin.

Lastly, vitamin A, the great balancer of the skin. My favourite forms of active vitamin A are retinol (make sure its stabilised, preferable as a liposome) and the new Rolls Royce version, hydroxy pinacolone retinoate (HPR). Vitamin A is excellent for addressing fine lines, balancing oil production, reducing pigmentation, regulating the production of fresh new skin cells, and it can even reverse sun damage. Pretty impressive, huh?

Is there anything we should avoid or be cautious of?

Introducing active ingredients into your routine should be done with careful consideration. First and foremost, I always recommend heading in for an in-depth consultation with a skin therapist. You may look at your skin in the mirror and see redness; however, a trained clinician will be able to identify underlying concerns such as sun damage and prescribe an active ingredient accordingly. There are thousands of actives ingredients on the market, but you need to find the ones that will serve YOU. Avoid buzzwords and on-trend hype products and instead, work with a clinician or brand to curate a personalised routine to suit your unique skin concerns.