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  • Published: 2 August 2026
  • ISBN: 9781529155228
  • Imprint: Hutchinson Heinemann
  • Format: Hardback
  • Pages: 352
  • RRP: $55.00

The Shampoo Effect




An accidental pregnancy turns a tight-knit group on its head in this witty and irresistible novel of modern love, sex, and friendship, from the New York Times bestselling author of PINEAPPLE STREET (‘Blissfully enjoyable’ India Knight).

A VOGUE 'BEST BOOK OF 2026'

‘I devoured The Shampoo Effect . . . it's funny, drama-fuelled, and full of Jackson's breezy wit.’
Coco Mellors, Sunday Times bestselling author of BLUE SISTERS

'So breezily readable and laugh-out-loud funny while excavating the deepest truths about motherhood, family, and forgiveness.'
Catherine Newman, author of WE ALL WANT IMPOSSIBLE THINGS

'An absolute DELIGHT . . . a must, must, must for your summer reading list'
Elin Hilderbrand, New York Times bestselling author of THE PERFECT COUPLE

'Funny, sharp and charming'
Rebecca Serle, New York Times bestselling author of IN FIVE YEARS

'A frothy, exuberant book'
Vogue

OVER ONE LONG SUMMER, WHO KNOWS WHAT MIGHT COME OUT IN THE WASH?

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

'[A] juicy send-up of privilege in all its rowdy dysfunction'
People

'Astutely observed'
Booklist

  • Published: 2 August 2026
  • ISBN: 9781529155228
  • Imprint: Hutchinson Heinemann
  • Format: Hardback
  • Pages: 352
  • RRP: $55.00

About the author

Jenny Jackson

Jenny Jackson is Editor at Knopf. She graduated from Williams in 2001 and attended the Columbia Publishing Course in 2002. She began her career at Vintage and has worked at Knopf for 19 years. Jenny's authors include Chris Bohjalian, Jennifer Close, Kevin Kwan, Emily St. John Mandel, Erin Morgenstern, and J. Courtney Sullivan.

Also by Jenny Jackson

See all

Praise for The Shampoo Effect

I devoured The Shampoo Effect. Jackson has a rare knack for capturing the intensity of old friendships and the way love, jealousy, money, and history combust until everyone is behaving (deliciously) badly. It's funny, drama-fueled, and full of Jackson's breezy wit, but what stayed with me most was how honestly and insightfully it captures the grit beneath the gloss of these characters. A brilliant story of marriage, motherhood, and the difficult work of breaking old patterns to become someone new

Coco Mellors, New York Times bestselling author of BLUE SISTERS

An absolute DELIGHT. This book has everything I love in a beach read: a coastal setting, multiple points of view, compelling storylines, and a delicious specificity to the writing that makes every single sentence feel fresh and alive. Jenny Jackson’s The Shampoo Effect is a must, must, must for your summer reading list.

Elin Hilderbrand, #1 New York Times bestselling author of SWAN SONG

Funny, sharp, and charming

Rebecca Serle, New York Times bestselling author of ONE ITALIAN SUMMER

The Shampoo Effect is a delicious, unputdownable portrait of a group of friends navigating love, marriage, and young parenthood. Jackson's characters are fully drawn, complex and flawed, each traveling a true arc of growth, arriving in the final pages at a deeper understanding of the ties that bind them to one another. I loved it

Belle Burden, #1 New York Times bestselling author of STRANGERS

One of the smartest, funniest, and most astute novels I've ever read . . . presented by Jenny Jackson with a combination of great humour and profound wistfulness. I loved this novel. You will, too.

Chris Bohjalian, author of THE FLIGHT ATTENDANT and THE AMATEUR

I binged The Shampoo Effect and am now bereft and also jealous. Jenny Jackson has written a book that's so breezily readable and laugh-out-loud funny while excavating the deepest truths about motherhood, family, and forgiveness. What an unforgettable cast of characters. What an accomplishment.

Catherine Newman, author of WE ALL WANT IMPOSSIBLE THINGS

Warm, witty, sharp and clever – it's the perfect smart summer book. Absolutely delicious!

Daisy Buchanan, author of CAREERING

Smart, funny, and perceptive, Jenny Jackson captures the messiness of modern relationships with rare precision. THE SHAMPOO EFFECT is an addictive, beautifully observed read.

Louise O'Neill, author of ASKING FOR IT

The platonic ideal of a beach read: fun and fast-paced, with a cover that screams, "Can I borrow your sunscreen?" It also features one of my favourite setups (dating back to "Up Island," by Anne Rivers Siddons), in which an outsider arrives in a clubby enclave and makes waves. ... Here, [Jackson] delivers us to the land of clam rolls with [an] anthropological eye.

New York Times

In this juicy send-up of privilege in all its rowdy dysfunction, a writing fellowship brings nepo baby Caroline Lash to small-town New England. There, she falls for a local environmentalist with a cliquey friend group that will soon regret freezing her out.

People

Jackson paints a nuanced, empathetic, distinct picture of each woman, exploring different views on marriage, parenthood, career aspirations, and adulthood... This astutely observed story is funny and gossipy without veering into the mean-spirited. Hand this to readers who love Emma Straub, Amy Poeppel, and Katherine Heiny.

Booklist (starred review)

Jackson rotates the point of view around the set of friends, deftly depicting the practices and pressures of modern parents... This easy read combines a literary rom-com with an acute portrait of midlife among millennials.

Kirkus

A frothy, exuberant book.

Vogue

A fantastic character-driven read.

Shelf Awareness

Meant to be read on a sweltering July day, with sand between your toes. Like Jackson's popular debut, Pineapple Street, this is one of those rare books that feel both breezy and meaty, sharp but empathetic.

Toronto Star

The Shampoo Effect is a stylish, sharply observed novel about image, reinvention, and the chaos simmering beneath polished lives. It's perfect for readers who love emotionally messy characters with great taste...

The Sunday Series

Jackson has a knack for local color and well-rounded character work... this has plenty of heart.

Publishers Weekly

A smart, sly gloss on Updike's tales of marital unrest. So funny, so compelling, this novel hit home with me in its examination of the ways secrets can erode families and friendships.

Joanna Rakoff, international bestselling author of MY SALINGER YEAR