Interview With L’Oréal Senior Makeup Chemist Roselin Rosario |
Photo: Chaunte Vaughn

#WomanCrushWednesday celebrates our favorite influencers and cool girls who work in beauty.

Here, Roselin Rosario, L’Oréal Senior Chemist shares how she got started in makeup chemistry, her favorite L’Oréal product she’s worked on, her advice she has for aspiring beauty science junkies — and what makeup means to her.

Where did you grow up, and how did you get started in beauty?


I grew up in Aibonito, Puerto Rico, and I remember always been interested in beauty but not from a scientific perspective as I do now. Beauty and cosmetics are a big part of the Puerto Rican culture; you put makeup to leave the house even if it is to the front yard. Also, my mom had a part-time job as cosmetic consultant and seller so I got a lot of exposure to beauty products. I’ve absolutely love nail polish since elementary school, but was not allowed to use it. Since high school I started using nail polish, eyeshadows and mascara.

What was your first job?


My first job was in college, and I worked part-time as a new product demonstrator and promoter directly to consumers. I mainly worked with household and personal care products. It was challenging as I consider myself shy and I had to push myself to talk to people, explain the products and secure a purchase. After my PhD I worked at Ingredion Global Innovation Group developing innovative natural-based ingredients and additives for personal care and home care consumer products.


How has working in makeup impacted your life, and what moment in your career are you most proud of?


Working in makeup has impacted my life greatly. Not only I am more knowledgeable of the products I should use and how to use them, I also get to see and understand how makeup impacts others. I have been fortunate to witness consumer feedback about how makeup gives them confidence, help them go through a though time or bring happiness through color and transformation. Seeing a product I invented or work on in the market and learning how much people love them makes me feel very proud.

What is your favorite job that you've worked on?


The development of the Maybelline SuperStay Matte Inkformula. This was my first project at L’Oréal; I learned a lot about lipstick formulation from it and got my first patent applications at L’Oréal for inventing the formula.


⭐️GIVEAWAY ALERT!⭐️ We will have a #superstaymatteink themed room at the @colorfactoryco in NYC! We’re giving away 10 sets of tickets for opening week, August 20 – August 26, to a few lucky babellines! Starting with this post, here’s how to win tickets for you and a friend: 1️⃣ Follow @maybelline and @colorfactoryco on Instagram 2️⃣ Like this post 3️⃣ Tell us in the comments, what’s your favorite color of makeup to wear 4️⃣ Tag your bestie with #maybellinesweepstakes Keep an eye out on our page for more chances to enter through 8/10! Good luck! ❤️ See Rules: and must be in the US to enter!

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If you weren't a makeup chemist, what would you be doing?


I think I would be a cupcake baker. I love baking and much more decorating cupcakes. There is so much science in baking, and is so similar to formulating cosmetics — maybe that is why I like it so much.


What's your favorite product at the moment?


Currently, I am in love with IT Cosmetics Superhero Mascara because it gives me the look I am looking for, does not smudge and is easy to remove at the end of the day. I am a huge mascara fan, mascara and nail polish are the two product I cannot live without.


What's your advice for an aspiring makeup chemist?


My advice comes down to four key points. First, I recommend you get your technical/scientific education so you can understand the science behind the products. If you do not know the chemistry it would be difficult to innovate. Second, be curious, start learning from the products you already have. Read the ingredient list, and search what they are used for and what their chemical properties are. Third, while in school try to have a project related to cosmetics and if you can do an internship in a place like L’Oréal. And fourth, if you are really passionate, reach out to someone you know that can become your mentor on this field.


Finally, what does makeup mean to you?

To me, makeup is the instrument to be whomever we want to be.

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