THE NEW YORK TIMES BESTSELLER
A READ WITH JENNA BOOK CLUB PICK
A VOGUE 'BEST BOOK OF 2026

When writer Caroline Lash arrives in Greenhead, she falls immediately for its scenic beaches and New England charm – and even harder for Van Whittaker, a gorgeous, fleece-wearing, litter-collecting, kayak enthusiast.

She meets his friends: Augusta, old money and uptight; Fran, drowning in everyone else’s problems whilst keeping two kids (and an inebriated husband) afloat; and Bailey, who is sexy, confident . . . and inconveniently pregnant with Van’s child.

Determined nothing will dull the shine of her new romance, Caroline joins the friends as they run wild through Greenhead, drinking on houseboats, gossiping on beaches while their children paddle, and playing risky games.

It seems the fun will last forever – until it doesn’t. As decades-old friendships and marriages begin to fracture, Caroline’s place in their world is called into question. And with all the group’s most tightly held secrets at stake, who knows what might come out?

Dazzlingly funny, sexy, and as juicy as it is astute, THE SHAMPOO EFFECT is a story of late-night parties, early mornings with small children, and old friends finally growing up – despite all their best efforts.

'The platonic ideal of a beach read: fun and fast-paced' New York Times

'An absolute DELIGHT . . . a must, must, must for your summer reading list' ELIN HILDERBRAND, New York Times bestselling author of THE FIVE STAR WEEKEND

‘A delicious, unputdownable portrait of a group of friends navigating love, marriage, and young parenthood…I loved it.’ BELLE BURDEN, bestselling author of STRANGERS

© Jenny Jackson 2026 (P) Penguin Audio 2026