We're partnering with The Financial Diet because we both share the same common belief, informed decisions lead to better results. Understanding the basics helps you make choices that actually serve you. Partnering with The Financial Diet lets us bring that same transparency to skincare, so you can spend smarter and make more confident, informed, and empowered decisions as a consumer.

Great question! Most importantly: TFDIEUX gives you 15% off your order on dieuxskin.com. Only offered to The Financial Diet community.

The rest of the terms are as follows: 1 use per customer. Not combinable with other discount codes or promotional offers. Not valid on the purchase of bundles/gift sets, or products purchased on subscription. Offer ends 11:59p PT 4/30/2026. Other restrictions may apply.

Layering your products in the correct order is key to getting the most out of your routine. To keep it simple, follow the “thinnest to thickest” rule. Lightweight, water-based products like toners and serums should go on first, while richer creams and oils come later. This allows each product to absorb properly before you go in with the next.

Every Dieux product goes through a rigorous testing process to ensure safety, stability, and proven results, no shortcuts. We start with stability testing to confirm the formula holds its texture, color, and active ingredient potency over time, followed by compatibility testing in the final packaging to make sure the product performs as intended from first use to last.

Next, we conduct safety testing, including:
1.) HRIPT to ensure the product is non-irritating
2) PET to confirm preservatives protect against mold, yeast, and bacteria
3) Non-comedogenic/non-acnegenic testing to ensure it won't clog pores or trigger breakouts
4) Ocular safety testing (even for products not intended for eyes) as a precaution

For performance, we run clinical efficacy testing via third-party labs using trained graders and advanced skin analysis tools, alongside consumer perception studies to gather real-world feedback.

All third-party testing is conducted at independent, validated labs to ensure unbiased results. The exact timeline varies by product, but most formulas undergo the full suite of tests before launch, ensuring every claim we make is backed by both science and user experience.

At Dieux, we try to avoid unnecessary waste, opting for recycled or low-impact materials whenever possible. We like to call it making “better trash.” Because while sustainability is a moving target, it's one we'll always aim for.

We design products to be fully recyclable or reusable (like our Forever Mask, meant to replace single-use sheet masks), and we choose lightweight packaging to help lower shipping emissions. As a small team, we know all consumption has a footprint, so we conduct bi-quarterly packaging reviews to keep improving and adopt new innovations as they become available. Always aiming to Dieux better.