As part of the ideation process, Justin and his co-founder wanted papaya to be the main ingredient—and the star of the product. 

Papaya was chosen as a differentiating factor in the market. So, it isn't the case that papaya enzymes are some kind of elixir. Justin shared that ingredients have to work in concert with each other so most serums will contain various other extracts at different concentrations. 

For example, Lavishs serum contains sodium hyaluronate (for moisturising and soothing), Vitamin B3 or niacinamide (lightens and evens the skin tone), salicylic acid (exfoliates and reduces skin inflammation), Vitamin C (brightens the skin, reverses skin ageing, and lessens the pigmentation of age spots and freckles), goji extract (offers long-term anti-ageing benefits and immediate firming results), carrageenan (locks in the skin’s moisture) and papaya enzyme (stimulates skin renewal).

The concentration of each compound must be balanced and these compounds are the costliest part of the serum. The exact percentage or volume used are of course, a trade secret. 

So, don't go looking at products thinking a certain extract is the one and only 'correct' extract. That cucumber extract face cream may look exceptionally effective, but remember that the final composition of the product is what matters. 

Other factors also include the feel of the product on your skin, which will determine if the serum will be water-based or oil-based for example. Going further, the product might be customised to age groups, gender, and environmental concerns.