Turning 25? Here's What Happens to Your Collagen—and Why It's Worth Paying Attention

October 18, 2026

Your 25th birthday marks a new chapter. Your skincare routine can grow with you.

There are certain birthdays that feel like milestones.

At 18, you're officially an adult. At 21, you're discovering new freedoms. And by 25, you might be settling into your career, becoming more intentional about your health, or simply thinking differently about your future.

But there's another change happening beneath the surface—one you might not notice in the mirror just yet.

Your skin is changing, too.

As we move through adulthood, the natural processes associated with skin aging become increasingly relevant. One of the most important involves collagen, the protein responsible for much of your skin's structure, firmness, and strength.

It's not something to worry about. It's simply something worth understanding.

What Actually Happens to Your Skin at 25?

Collagen is one of the most abundant proteins in your body. In your skin, it forms part of the supportive framework that helps maintain firmness and resilience.

When we're younger, our skin is generally efficient at maintaining this structural network. But as we move through adulthood, the balance between collagen production and breakdown gradually changes.

Research suggests that collagen density in the skin may decline by approximately 1% per year throughout adulthood, although the rate varies from person to person.

There isn't a biological switch that flips on your 25th birthday. Collagen production doesn't suddenly stop, and your skin doesn't change overnight.

Instead, it's a gradual process influenced by genetics, sun exposure, lifestyle, and the natural passage of time.

In your 20s, your skin might still look and feel much the same as it did a few years earlier. That's normal.

The changes associated with collagen loss, including fine lines, reduced elasticity, and changes in texture, typically develop over years rather than days.

And while aging is inevitable, the habits you establish early can make a meaningful difference in how you care for your skin over time.

Why Your Mid-20s Are a Good Time to Rethink Skincare

For many of us, our teenage skincare routines were pretty straightforward: wash your face, deal with the occasional breakout, maybe remember to moisturize.

But as your skin and lifestyle evolve, your routine can evolve with them.

It's less about correcting something that's wrong and more about understanding what your skin needs.

Three ingredients worth getting familiar with are vitamin C, retinol, and peptides.

They each have different roles in skincare, and understanding those differences can help you build a routine without feeling overwhelmed by endless products and trends.

Vitamin C: Supporting Your Skin During the Day

Every day, your skin is exposed to environmental stressors, including ultraviolet radiation and pollution. These exposures can contribute to oxidative stress, which plays a role in premature skin aging.

Vitamin C is an antioxidant that helps neutralize free radicals. It's also involved in the body's natural collagen synthesis process.

In skincare, well-formulated vitamin C products can help brighten the appearance of skin, improve uneven tone, and reduce the appearance of certain dark spots.

For this reason, vitamin C has become a popular addition to morning routines.

DOMI's Vitamin C + Ferulic Acid Brightening Serum brings together vitamin C and ferulic acid, another antioxidant ingredient.

It's a simple way to incorporate antioxidant care into a routine, especially if dullness or uneven skin tone is something you've started noticing.

Of course, vitamin C isn't a replacement for sunscreen. Daily sun protection remains one of the most effective ways to limit preventable skin damage.

Retinol: Understanding Skin Renewal

Your skin is constantly renewing itself. Older surface cells are shed as new ones take their place. Over time, this renewal process can become less efficient, contributing to uneven texture and changes in the skin's appearance.

Retinol, a derivative of vitamin A, is one of the most extensively studied ingredients in skincare.

It helps encourage skin cell turnover and, with consistent use, can improve the appearance of fine lines, uneven texture, and certain forms of discoloration.

Retinoids also have evidence supporting their role in improving aspects of the skin's collagen structure.

But retinol isn't something everyone needs to start using the moment they turn 25. Your skin type, concerns, and tolerance matter.

For those who choose to incorporate it, starting slowly is important. Retinol can cause dryness or irritation, particularly when first introduced.

DOMI's Retinol + Peptide Renewal Serum brings these two ingredient categories together in a nighttime serum.

It's intended for nighttime use and can become part of a gradual, consistent routine. The goal isn't to rush visible changes. It's to give your skin appropriate care over time.

Retinol should be avoided during pregnancy. If you're pregnant, trying to conceive, or breastfeeding, speak with your healthcare professional before using retinoid products.

Peptides: Small Molecules With an Interesting Role in Skincare

Peptides might be one of the most interesting ingredients to understand as you become more intentional about skincare.

They're short chains of amino acids, the building blocks that make up larger proteins, including collagen and elastin.

Some peptides also function as biological messengers, helping regulate processes within the body.

Scientists have identified different categories of cosmetic peptides, each studied for particular functions.

Signal peptides are being investigated for their ability to influence processes involved in maintaining the skin's structural proteins.

Carrier peptides, including certain copper-related peptides, have been studied for their roles in cellular processes associated with skin maintenance and repair.

Other peptides have been explored for their potential effects on expression lines and enzymes involved in protein breakdown.

The science is promising, although research into the real-world benefits of many topical peptide formulations is still developing. Results depend on the particular peptide, its concentration, and the overall formulation.

What makes peptides particularly appealing in an everyday routine is their potential to complement other skincare ingredients.

DOMI's Peptide Barrier Moisturizer focuses on hydration, skin comfort, and supporting a smoother, more supple-looking complexion.

Because keeping your skin hydrated and maintaining its moisture barrier are valuable at any age. And sometimes, the most helpful skincare habit isn't adding more active ingredients. It's simply taking better care of the skin you have.

Building a Skincare Routine at 25 Doesn't Have to Be Complicated

One of the biggest misconceptions about skincare is that more products automatically mean better results. In reality, consistency and suitability matter far more than the number of steps in your routine.

A thoughtful routine might look something like this:

Morning: Protect and Hydrate

Cleanse gently with a product suited to your skin.
Apply a vitamin C serum if it works for your skin.
Follow with a moisturizer, such as a peptide-based moisturizer.
Finish with broad-spectrum SPF 30 or higher sunscreen.

Evening: Cleanse and Care

Remove sunscreen, makeup, and daily buildup.
Apply a retinol product on appropriate evenings if it's suitable for you, starting gradually.
Follow with moisturizer to support hydration and comfort.

You don't need every ingredient, and you don't need to introduce everything at once.

Some skin types benefit from a very simple routine. Others may have particular concerns that make targeted ingredients useful.

The best routine is the one that works for your skin and that you can maintain comfortably.

Your Skin Doesn't Change Overnight. Neither Should Your Relationship With It.

Turning 25 doesn't mean you're suddenly getting old. It doesn't mean wrinkles are around the corner. And it definitely doesn't mean you should start worrying about every little change in the mirror.

But it can be a meaningful time to think about the habits you're building.

You might start prioritizing sleep, eating more intentionally, or finding ways to manage everyday stress. Skincare can be part of that same conversation.

Not because there's something you need to fix, but because caring for yourself is something that can grow with you.

At DOMI, we see skincare as a daily ritual rather than a race against aging.

A little knowledge. A few thoughtful ingredients. And the consistency to make those habits your own.

Make 25 a Milestone Worth Remembering

Some birthdays mark what you've accomplished. Others mark what you're becoming. Your 25th birthday can be a little of both.

A chance to celebrate how far you've come—and perhaps begin a few habits you'll appreciate years from now.

You don't need to stop aging. You don't need perfect skin. And you don't need a complicated routine to begin taking care of yourself.

Twenty-five isn't a deadline. It's a beginning.

Here's to growing, changing, and feeling comfortable in your skin through every chapter.

DOMI — Skincare that grows with you.