Copper peptides are known for their skin rejuvenating properties and are often found in anti-aging skincare products. However, there are certain ingredients that should not be mixed with copper peptides to avoid any potential negative interactions or reduced efficacy. Here are some ingredients to avoid combining with copper peptides:

1. Vitamin C: Copper peptides and vitamin C have been found to have a chemical reaction that can degrade both ingredients, reducing their effectiveness. It is best to use them at different times, such as using vitamin C in the morning and copper peptides in the evening.

2. AHAs/BHAs: Alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs) are exfoliating agents commonly found in skincare products. When used together with copper peptides, they can potentially increase skin sensitivity and irritation. It is advisable to use them on alternate days or at different times of the day.

3. Retinol: Retinol is a potent anti-aging ingredient that can enhance cell turnover and collagen production. However, when combined with copper peptides, it can lead to skin irritation and potential instability of both ingredients. It is best to use them separately, such as retinol in the evening and copper peptides in the morning.

4. Benzoyl Peroxide: Benzoyl peroxide is commonly used to treat acne due to its antibacterial properties. However, when combined with copper peptides, it can potentially reduce the effectiveness of both ingredients. It is recommended to use them at different times or consult a dermatologist for guidance.

5. Hydroquinone: Hydroquinone is a skin-lightening agent used to treat hyperpigmentation. When combined with copper peptides, it can potentially lead to skin irritation and reduced efficacy of both ingredients. It is advisable to use them separately or under the guidance of a skincare professional.

It is important to note that individual reactions may vary, and it is always a good idea to consult with a dermatologist or skincare professional before incorporating new ingredients into your skincare routine.