Skincare can feel overwhelming, but it doesn’t have to be - Caroline Hirons

Skin Rules, Caroline Hirons’ bestselling guide to skincare, offers expert advice to help readers better understand their skin and make informed choices about their routines. As a respected skincare expert, author and aesthetician, Caroline is known for her straightforward, honest approach to skincare and her ability to cut through the noise.

For By Sarah, this is something we’ve always believed in.

Nine years ago, we started By Sarah with a shared vision: to create effective, nurturing skincare for sensitive skin. We couldn’t have known where that journey would take us, but the purpose behind what we do has remained the same.

Today, seeing four of our award-winning products featured in Caroline Hirons’ Skin Rules feels like a real pinch-me moment. For a sister-founded brand, it’s a milestone we’re incredibly proud of.

The Care Behind Our Formulations

By Sarah began with a very personal experience. When co-founder Lauren was diagnosed with acute myeloid leukaemia, Sarah became her stem cell donor. During this time, caring for Lauren and seeing the changes she experienced helped inspire Sarah to explore skincare in a more personal way. What began with a desire to care for her sister eventually grew into skincare By Sarah.

That experience continues to mean a great deal to us. It shaped the way we think about skincare and reminded us how important it is to understand the needs of the skin, particularly when it feels more sensitive or needs extra care.

Over the years, we’ve continued to learn, listen to our customers and refine our formulations. We know there is always more to discover, and we want that curiosity to remain part of how we develop our products as the brand grows.

The Four By Sarah Products Featured in Skin Rules

The four By Sarah products featured in Skin Rules are Reviver Hydrating Mist, Tender Skin Balm Moisturising Cream, Vitamin C+E Facial Oil and Serene Daily SPF 50+. Each has its own purpose, from helping to hydrate and nourish the skin to providing daily sun protection.

Table of contents

• Reviver Hydrating Mist
• Tender Skin Balm Moisturising Cream
• Vitamin C+E Facial Oil
• Serene Daily SPF 50+
  

Reviver Hydrating Mist

“Soothe red, dry or irritated skin in one hydrating spritz.”

During the colder months, skin is constantly adjusting to changing environments. Cold winds, damp weather and frosty mornings give way to centrally heated homes, offices and shops, where dry indoor air can leave sensitive skin feeling uncomfortable. This repeated exposure can make redness, tightness and irritation more noticeable, particularly for skin that is already prone to sensitivity. A little extra soothing care can help keep skin feeling calm throughout the day.

Reviver Hydrating Mist offers more than a quick refresh. Its prebiotic formulation helps soothe irritation and support the skin barrier and microbiome, keeping your skin feeling calm and comfortable.

It’s also ideal for a mid-day refresh. Pollution and air-conditioned spaces can leave skin feeling parched, so keep it close for a refreshing spritz whenever needed, even over makeup.

Why you'll love it:

• Everyday hydration: Helps keep skin feeling fresh, hydrated and comfortable throughout the day.
• Soothing comfort: Helps calm dry, irritated skin.
• Skin barrier support: Helps maintain a healthy skin microbiome.

When to use it: Morning and evening after cleansing, or throughout the day as needed. It can also be spritzed over makeup.

How to use it: Spray onto cleansed, damp skin and gently press into the face and neck before applying your moisturiser and facial oils.

Tender Skin Balm Moisturising Cream

“Your skincare first-aid kit.”

Winter can be especially demanding on skin that is already dry or delicate. Between chilly walks, cold winds and the drying effects of central heating, skin can lose its softness and become rough, tight and uncomfortable. Hands, cuticles and exposed areas of the face and body often need particular attention, especially during periods of frequent handwashing and exposure to the elements. A nourishing moisturiser can help restore comfort and keep these areas feeling soft and cared for.

Tender Skin Balm Moisturising Cream is a lightweight, all-over moisturiser enriched with Madecassoside, prebiotic inulin and nourishing plant butters. It helps soften dry skin, soothe redness and itchiness, and support the skin barrier to reduce moisture loss.

Why you'll love it:

• Nourishing moisture: Helps soften and moisturise dry skin.
• Soothing care: Helps relieve feelings of redness and itchiness.
• Barrier support: Helps maintain the skin barrier and a healthy microbiome.

When to use it: Morning and evening, or whenever dry or sensitive areas need extra care.

How to use it: Apply to the face and neck after cleansing and before facial oils. Massage generously into hands and body wherever extra moisture is needed.

Vitamin C+E Facial Oil

“Vitamin C (but not as you know it).”

The shorter days and darker skies of autumn and winter can make maintaining a healthy-looking glow feel more challenging. Alongside colder temperatures and dry indoor air, seasonal changes can leave skin looking tired, lacklustre and in need of some extra nourishment. When your complexion starts to lose its usual radiance, adding a targeted facial oil to your routine can help bring back a softer, more luminous appearance.

Vitamin C+E Facial Oil combines a gentle, slow-release form of Vitamin C (Ascorbyl Tetraisopalmitate) with Vitamin E to help nourish the skin, soothe and boost radiance. We've also added luxurious plant oils to revitalise and leave skin feeling soft and nourished.

Why you'll love it:

• Boosts radiance: Helps brighten the appearance of dull, lacklustre skin.
• Gentle Vitamin C: A slow-release, oil-soluble form designed to be well tolerated, even by sensitive skin.
• Nourishing oils: Helps soften and revitalise the skin.
• Vitamin E support: Helps soothe the skin and boost the efficacy of Vitamin C.

When to use it: Use daily as part of your morning skincare routine, before applying SPF and makeup.

How to use it: For best results, apply 1 pump to cleansed, damp skin, or mix it with your moisturiser for an added boost of nourishment and radiance.

Serene Daily SPF 50+

“Every day is a sunscreen day.”

As autumn turns to winter, shorter days, grey skies and colder temperatures can make sun protection easy to overlook. Yet even on overcast days, your skin is still exposed to UV rays during everyday activities, from the morning commute to a lunchtime walk. Keeping SPF in your daily routine remains just as important when the sunshine fades.

Serene Daily SPF 50+ is a dermatologically approved, lightweight sunscreen designed for sensitive skin. It provides broad-spectrum UVA and UVB protection with a fast-absorbing, moisturiser-like feel and no sticky finish.

Enriched with ginseng, apple and peach extracts, its antioxidant-rich formula helps hydrate and comfort the skin while providing additional support against environmental stressors. Suitable for all skin tones, it makes daily SPF an easy and comfortable part of your routine.

Why you'll love it:

• Broad-spectrum protection: SPF 50+ helps protect against UVA and UVB rays.
• Lightweight feel: Fast-absorbing with a comfortable, non-sticky finish.
• Sensitive skin friendly: Formulated to provide comfortable daily protection.
• Antioxidant support: Ginseng, apple and peach extracts help hydrate and support the skin against environmental stressors.

When to use it: Every morning as the final step in your skincare routine.

How to use it: Apply generously to the face and neck before sun exposure. Reapply regularly, particularly after swimming, sweating or towelling.

Recognition from a Trusted Voice

Described by The Business of Fashion as “arguably the most important figure in British beauty”, Caroline Hirons is an advanced aesthetician, skincare expert and Sunday Times bestselling author. After beginning her career at Harvey Nichols in Knightsbridge, she launched her blog in 2010 and later founded her skincare brand, Skin Rocks. She is known for her honest, science-led approach to skincare.

Having four of our products featured in Skin Rules gives us an opportunity to reflect on how far By Sarah has come while staying true to the purpose that started it all. Each product represents our continued commitment to thoughtful formulations and understanding what the skin needs.

Nine Years On, Our Purpose Remains

What began as a shared vision between two sisters has grown into a brand that continues to evolve. Looking back, we're grateful for everything the journey has taught us and for the people who have supported us along the way.

There is still so much we want to learn and develop. As we look ahead, we hope to keep growing with the same care and intention that brought us here.

In Summary

• A proud milestone: Four By Sarah products feature in Caroline Hirons’ Skin Rules, marking a special moment for our sister-founded brand after nine years of growth.
• Our journey: Nine years of learning, developing and creating thoughtful, nurturing skincare.
• Featured products: Reviver Hydrating Mist, Tender Skin Balm, Vitamin C+E Facial Oil and Serene Daily SPF 50+.
• Looking ahead: Continuing to develop thoughtful skincare while staying true to the vision behind By Sarah.

Continue exploring

• By Sarah named #1 on the British Beauty Brands List 2025
• IWD 2026: Meet the Sisters Behind By Sarah
• Behind the scenes: the making of By Sarah with Sarah & Lauren

For more from By Sarah, follow @bysarahlondon, where we share what we’re learning about skin, wellbeing and the things that can make a real difference day to day, alongside nutrition and gut-health insights from our Co-founder and Registered Nutritionist, Sarah.

And if this article has left you with a question, or there’s something you’d like us to explore next, we’d genuinely love to hear from you. You can always message us at care@bysarahlondon.com.

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