Your ritual for perfect lashes.

Love your natural lashes again.

Naturally longer. Noticeably fuller.

Our mission

Line Theory was created for lashes and brows that no longer feel quite like yours: finer, shorter, sparser or more fragile than they used to be. At the heart of our formulas is PACT-17®, our peptide-led conditioning complex designed to help lashes and brows look fuller, feel softer and appear healthier over time. Choose Intensive when you want a more targeted performance formula with a prostaglandin analogue. Choose Precision when you prefer a prostaglandin-free, comfort-led routine. Every formula is designed around the same philosophy: visible definition, daily consistency and care that respects the delicate eye area.

ABOUT US

Customer Testimonials

★★★★★

“Longer-looking lashes without extensions.”

I wanted something to help my natural lashes look longer and more defined, and this has really impressed me. My lashes look healthier, softer and more noticeable, especially with mascara. I’ll definitely be repurchasing.

Hannah L.

★★★★★

“Feels premium from start to finish.”

This lash serum feels like a real treat. The packaging is beautiful, the applicator is precise, and the formula feels lightweight and comfortable on my lash line. My lashes look healthier and fuller, and I love how easy it is to include in my routine.

Charlotte B.

★★★★★

“My lashes look so much fuller.”

I’ve been using this serum every evening for a few weeks and my lashes already look noticeably fuller and healthier. The formula feels lightweight, doesn’t sting, and sits really nicely along the lash line. It feels like a genuinely premium product.

Sophie M.

★★★★★

“Beautiful packaging and a luxury feel.”

From the moment it arrived, everything about this serum felt high-end. The packaging is sleek and elegant, and the applicator makes it really easy to use. It has become a lovely part of my evening routine.

Amelia R.

PACT-17® Proprietary Formula

Powered by science, rooted in nature

Vegan & Cruelty-Free

100% vegan and never tested on animals

Climate Neutral Certified

Eco-friendly skincare for you and the planet