Sarah K Sunset Leave-In Anti-Frizz Spray - Heat Protection - 200ml is the leave-in for the months when hair takes the most punishment. Flat irons and hairdryers on one side; chlorine, salt water and long afternoons of UVA and UVB rays on the other. Sunset answers both. Shake, spray from about 20 cm, and a fine mist settles over clean hair: panthenol and keratin work into the surface while shea butter and hyaluronic acid keep the feel soft, not starchy. Nothing to rinse. 200ml of home care, built for the pool bag as much as the bathroom shelf.

Why a summer leave-in earns its place

Hair does not need to be near a flat iron to feel heat. A hairdryer, a curling wand, an afternoon on a sun lounger -- all raise the temperature of the fibre, and the fibre answers by giving up water. Add chlorine or sea salt and the cuticle roughens, the surface stops reflecting light evenly, and frizz turns up where it was not that morning. That is the ordinary physics of a summer.

Sunset works on the outside of that problem. The formula lays a light, even film over the strand -- a layer between your hair and whatever comes next. That is why one bottle covers both the straightener and the swimming pool: the barrier is the same in either case. Panthenol and keratin travel in on that film, while shea butter and hyaluronic acid keep the feel supple instead of coated.

Key ingredients

• Panthenol: a humectant that draws water in and holds it there, for softness and a less brittle feel
• Keratin: the protein hair is built from, working at the surface to help smooth a cuticle that heat and water have roughened
• Shea butter: a rich emollient that helps seal the outer layer and keeps the ends supple
• Hyaluronic acid: binds water at the surface without weight, so hydration does not cost you movement

What to expect

Expect hair that behaves. Combed through after spraying it detangles more easily and dries with fewer flyaways; under a straightener it feels less like the iron is dragging. Across a beach day the ends stay softer than they otherwise would. Be clear about what Sunset is not: it is not a rinse-out conditioner, not a repair product, and no substitute for a hat or for rinsing your hair with fresh water after a swim. It is a barrier -- useful, but not the same as immunity.

Who it is for

• Regular heat-stylers: if the hairdryer, straightener or wand comes out more than twice a week, this is the step before it
• Swimmers, sunbathers and holiday hair: made for pool, beach and UVA/UVB rays, and small enough to live in the beach bag
• Frizz-prone, dry or coloured hair: the lengths that go rough and dull fastest benefit most
• Anyone keeping smooth hair smooth: a light barrier before heat and water fits neatly into a maintenance routine

Who it is not for

• Silicone-avoiders: Sunset is a silicone-based formula and will not suit a curly-girl routine
• Very fine hair with a heavy hand: the mist is light, but over-spraying still weighs fine hair down. Use less than you think
• Anyone wanting a rinse-out conditioner: this stays in the hair. It is not a mask and not a wash-out step
• Scalp application: Sunset belongs on the mid-lengths and ends, not the roots

Professional tip

The thing most people get wrong is the timing. Sunset is a before product, not an after one -- before the iron, not once the hair is already hot; before the swim, not while you are towelling off. Heading into a pool? Wet your hair with clean water first: a strand already full of fresh water has less room left to soak up chlorinated water. Then mist Sunset through the lengths, comb it through so the coat is even, and tie the hair back. And keep the bottle in the beach bag, not the bathroom cabinet.

How to use

1. Shake the bottle before use.
2. Start with clean hair, washed beforehand.
3. Hold the bottle about 20 cm from the hair and mist evenly over the lengths.
4. Style as you like. Sunset stays in -- there is no rinsing step.

Using it alongside your smoothing routine

If your hair has been smoothed in a salon, summer is the season that tests the result. Sun, chlorine and sea salt are demanding on smooth hair, and the quick pass of a straightener between washes adds heat on top. Sunset is a sensible thing to have in the rotation: a few sprays on clean hair before you style, swim, or spend a long day outdoors. It sits alongside your maintenance shampoo and conditioner rather than replacing them. If your stylist has given you specific aftercare instructions, those come first.

In short

• One barrier, two jobs: heat from your tools, and sun, chlorine and salt from your summer
• Leave-in, no rinsing: shake, mist onto clean hair from about 20 cm, then style as usual
• Panthenol and keratin, with shea butter and hyaluronic acid for softness without weight
• Vegan and dermatologically tested. 200ml trigger spray, made in Brazil

Frequently asked questions