For products that reduce dark circles under the eyes, the crucial ingredients would be Vitamin C and K, as they deplete free radicals, brighten the skin and boost collagen. Vitamin K additionally comes with its own superpower in being a potent antioxidant too.
There are plenty of ingredients involved in the successful recipe of skincare products, which always require an expert in the matter to ensure your products are reliable, certified, and more importantly trusted by the consumer. Being trustworthy and authentic is key to success, as interestingly enough word of mouth recommendations have always been and will always be an incredibly successful form of marketing; especially in the cosmetic industry.