Agencies said the publisher had informed them that subsequent editions have sold about 120,000 copies on the news-stand, although industry sources said two recent issues sold less than 100,000, with one as low as 70,000, understood to be around a tenth of its print run.
Emap is ploughing £12m into the magazine, which was launched on 17 May, although it is thought to have held back a large part of the budget for later in the year.
Agencies have queried whether Emap had the right editorial mix ready for the launch of the magazine, and as with Grazia and Heat before it, expected the publisher to make changes in the months to come.
"It's a big issue to get people to sample it, as there's no established market for it. People are not going to the news-stand looking for this kind of magazine," said Mark Gallagher, press director at Manning Gottlieb OMD. "It's a new concept and will need some tweaking. The front end looks good, but the back is a bit disorganised."
Dom Williams, press director at Carat, added: "I would expect better figures by now. But it is a busier market now than when Emap launched Grazia and Closer, which have done well by being strong products."
Emap said it would not comment on speculative figures, but that it remained committed to its promise to post an ABC of at least 150,000 after a year on sale.
"We are really pleased with the overwhelming response we have received from advertisers, retailers and readers, given that First is carving out a whole niche in the women's weekly market," a spokesman said.
Louise Matthews, MD of Emap Entertainment, described the news- and picture-led magazine as an "empowering" lifestyle read for 30-something women with young children when she announced its launch.