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For decades, shampoo has been marketed around shinier hair, bigger volume, and fewer bad hair days. Rarely has the conversation focused on the scalp itself or the ingredients behind those promises. But as ingredient transparency becomes a bigger priority across wellness, more people are starting to rethink the products they use every wash day.
Carly Ferrarese, founder of Under Luna, has built her brand around that very idea. Ahead, she shares why the future of healthy hair starts with the scalp, how she approaches formulation differently, and why she believes it’s time we all paid closer attention to what’s in our shampoo.
Why You Should Rethink What’s in Your Shampoo
You’ve said your own non toxic journey began with questioning the lack of transparency in beauty. Why do you think shampoo ingredients have largely escaped the same scrutiny people now give skincare ingredients? Great question. Somewhere along the way, hair care became framed as cosmetic, while skincare became synonymous with self-care and ingredient awareness. But before shampoo was commercialized, hair care and the rituals around the scalp were part of daily life.
For me, skincare and scalp care have always been tied together. The scalp is skin, and it has many of the same needs as the skin on our face: a healthy barrier, balanced oil production, and thoughtful, supportive care. For decades, we’ve been taught to focus on facial skincare while largely overlooking the scalp. As a result, many people don’t realize how much the scalp influences the health of the hair. Once you begin viewing the scalp through a skincare lens, the entire conversation around hair care changes.
Haircare has historically been marketed around shine, volume, or repair, but recently there’s been much more conversation around scalp health. Why do you think that shift is happening now? Hair care has traditionally focused on surface-level results: more shine, more volume, less frizz. But scalp care asks a different question: what’s happening at the root?
People are becoming less interested in quick fixes and more interested in understanding the underlying causes of the issues they’re experiencing. We know there can be a strong connection between hormones and hair growth, just as inflammation, gut health, stress, and diet can often show up through the scalp, whether that looks like excess shedding, irritation, oil imbalance, or flakes.
As these concerns become more common, it feels important to start connecting those dots. The reality is, if we want real shine, real growth, and real repair, we have to look at the scalp first.
A lot of consumers are starting to realize that “clean” doesn’t always mean transparent. How do you personally define truly non toxic haircare? Unfortunately, “clean” doesn’t mean much on its own anymore. Many of these marketing claims aren’t clearly regulated, which is why transparency matters so much.
For me, truly non-toxic hair care starts with the ingredients. Under Luna was born from my own need for shampoo and conditioner I could truly feel good about using. I felt like real transparency was missing from hair care, and that became part of the mission: to create formulas where every ingredient had a purpose, and nothing was hidden behind vague claims.
We don’t add ingredients as fillers, and we don’t choose something because it looks good on a label or happens to be trending. We work closely with trusted suppliers, source many locally grown herbs, and put a tremendous amount of care into finding ingredients that are both safe and effective. We aren’t interested in performative clean beauty. We’re interested in formulas that are transparent, thoughtful, and truly support the scalp and hair. That level of quality is something you can feel.
What are some of the biggest “greenwashing” tactics you see in the haircare space today? One of the biggest forms of greenwashing I see is brands relying on buzzwords instead of transparency. Words like “clean,” “natural,” or “non-toxic” can sound reassuring, but they often have no clear definition behind them.
I also see brands highlighting one hero plant-based ingredient on the front of the bottle, while that ingredient may make up only a tiny part of the formula. True transparency means being willing to talk about the entire formula: where ingredients come from, why they’re included, and how they support the scalp and hair.
The most honest brands aren’t just selling an image of nature, they’re willing to show their work.
Under Luna’s formulas lean heavily on herbs and roots like white willow bark, horsetail, yarrow, chamomile, and yucca root. What drew you to these particular botanicals? I did a tremendous amount of research before creating my first shampoo samples. I kept coming back to the same questions: What is shampoo, really? How did we get here? What were people using before hair care became commercialized?
That curiosity led me into the origins of scalp and hair rituals across cultures and traditions throughout history. What drew me to these herbs is that many of them have been used for generations to cleanse, soothe, strengthen, and support the scalp and hair.
I love that they carry a story, but they’re not in our formulas just because they’re beautiful. They’re there because they have function. Each one brings something purposeful to the formula, whether it’s helping create a gentle lather, relieving an itchy scalp, calming flakes, or strengthening the hair. Plants are incredibly powerful when you understand how to work with them.
Yucca root is one ingredient that appears throughout your shampoos and isn’t something most consumers are familiar with. What makes it so special as a cleansing ingredient compared to more traditional surfactants? Yucca root is so special to me. It was one of the ingredients that opened up my entire scalp care journey. Once I began studying yucca, the formulas started to come together piece by piece.
Traditionally, yucca root was crushed or worked against stone to release its natural saponins, creating a gentle, soap-like lather for cleansing the scalp and hair. What makes yucca different from many cleansing agents is that it helps cleanse without stripping the scalp of its natural oils, which is so important when you think about the scalp as skin.
Our shampoos are designed to remove dirt, buildup, and excess oil while still protecting the scalp barrier and supporting pH balance. That’s why yucca appears throughout our shampoos. It’s gentle, effective, and foundational to the way we formulate.
Are there any ingredients commonly found in conventional shampoo that you personally avoid entirely when formulating? Yes, there are many ingredients I avoid entirely when formulating, but the biggest categories are synthetic fragrance, harsh surfactants, silicones, and preservatives that don’t meet our standards.
Fragrance is a big one because it can hide so much under one word, including undisclosed aroma compounds. I also avoid harsh cleansing agents that can strip the scalp barrier and leave people stuck in that cycle of dryness, irritation, and overproduction of oil. Silicones are another category I avoid entirely because they can create the temporary feeling of softness and shine, while masking what the hair and scalp actually need and contribute to buildup.
For me, it always comes back to the same questions: Where does this ingredient come from? What is it derived from? Is it something the body can recognize? And how does it benefit the scalp and hair?
Under Luna’s shampoos each seem to support different scalp needs and hair textures. Can you walk us through how you think about matching formulas to specific concerns? We always start with the scalp. Our shampoos are designed around scalp needs, while our conditioners are designed around the needs of the hair itself.
Because our shampoos are built around these intelligent plants, I’m able to layer in different herbs depending on the type of support the scalp needs. For someone who is more oily or dandruff-prone, we created Warrior Shampoo with herbs traditionally used to decongest the scalp and help rebalance oil production. For someone experiencing dryness, sensitivity, or irritation, Luna Clear Shampoo leans into herbs known for their soothing and restorative properties.
For balanced or fluctuating scalps, especially during periods of hormonal change like pregnancy, postpartum, and perimenopause, we created Tulsi Bloom Shampoo. In those cases, the goal isn’t to aggressively correct the scalp, but to help bring it back into balance.
That’s really at the heart of how we formulate: shampoo based on scalp needs and conditioner based on hair needs. Together, they support each other, helping the scalp and hair return to balance.
Warrior Shampoo has become one of your most recognizable formulas. What specific scalp or hair concerns were you trying to solve when creating it? Warrior was our very first shampoo formula, and it was created for the scalp that feels oily, congested, itchy, or dandruff-prone.
I wanted to create something that could deeply cleanse and help rebalance the scalp without stripping it. So often, people with oily or flaky scalps reach for harsh shampoos that over-strip the scalp, leaving it feeling tight, irritated, and even more reactive.
Warrior was designed to support that cycle differently: to help lift buildup, calm a flaky, itchy scalp, and leave it feeling clean, balanced, and like it can breathe again.
If readers take away just one thing from this conversation, what do you hope it changes about the way they think about their shampoo routine? If there’s one thing I hope people take away, it’s to become more in tune with their scalp.
The scalp tells a story. Just like we learn to read our skin, a breakout, dryness, irritation, congestion, we can begin to read the scalp in the same way. Oiliness, flakes, itch, buildup, sensitivity, or shedding can all be signals worth paying attention to.
When I’m under stress, I often notice a small dry patch appear right at my hairline, front and center, so I get the message loud and clear. It’s a reminder that the scalp is part of an incredible system, and often, it can be a reflection of what’s happening internally.
When you have a routine that is nourishing and supportive, washing your hair isn’t something to avoid. It becomes something you can turn to when your scalp feels out of balance.
For so long, we’ve been told not to wash our hair too much, but the issue isn’t shampoo itself, it’s what’s in the shampoo. I hope people begin to see their shampoo routine not as a chore, but as an opportunity to care for one of the most overlooked parts of the body.
The more we learn to listen to the scalp, the more we understand what it needs and what our body may need, too.
