Angelina Jolie's surprise announcement last year that she had undergone a preventative double mastectomy has helped double referrals for genetic breast cancer tests.
The actress took the decision after testing positive for the BRCA1 gene mutation, which greatly increases the risk of getting the disease.
A new study shows that in June and July last year the number of GP referrals for genetic counselling and DNA tests for breast cancer mutations in the UK increased two-and-a-half times compared with the same period in 2012.
The "Angelina effect" was long-lasting, with referrals remaining at twice the previous year's figure from August to October.
But the extra women seeking help were not worrying unnecessarily - most had a family history of breast cancer, meaning they were being appropriately screened.
Professor Gareth Evans, from the charity Genesis Breast Cancer Prevention and St Mary's Hospital, Manchester, who led the study published in the journal Breast Cancer Research, said: "Angelina Jolie stating she has a BRCA1 mutation and going on to have a risk-reducing mastectomy is likely to have had a bigger impact than other celebrity announcements, possibly due to her image as a glamorous and strong woman.
"This may have lessened patients' fears about a loss of sexual identity post preventative surgery and encouraged those who had not previously engaged with health services to consider genetic testing.
"Of course, in some cases this may mean a risk-reducing mastectomy, however cancer preventing drugs, such as tamoxifen, and certain lifestyle changes like a healthy diet and more exercise, are also options which many women may consider."
Defective versions of BRCA1 and its sister gene BRCA2 are together responsible for about a fifth of breast cancers.
Women who inherit BRCA1 have a 60% to 90% risk of developing breast cancer in their lifetime. BRCA2 increases the risk by 45% to 85%.
Both gene mutations also raise the risk of ovarian cancer.
The "Angelina effect" highlights the need for more to be done to improve awareness of inherited breast cancer, say the researchers.
Under NHS guidelines, women can qualify for BRCA testing if one of the mutations has already been identified in a relative or they have a strong family history of breast cancer.
Jade Goody's diagnosis and death from cervical cancer in 2009 had a similar impact among young women with a spike reported in cervical smear tests.
However, figures later showed that the effect had worn off by 2012 when the number of screenings fell to a 10-year low.