It's hardly women's favourite time of the month, but nevertheless, sanitary products are an essential purchase for most of them for a good proportion of their lives. More than seven in 10 users buy them as part of their regular shop.
With little positive emotion attached to the products, buying motivations focus on convenience, bulk and promotion, none of which helps the market's value. In 2009 it will be worth £298m, according to Mintel, but growth has been flat over the past couple of years. Between 2004 and 2009 it grew by 11%.
This sector includes tampons, sanitary towels, panty liners and feminine hygiene products such as washes and wipes. Although the first two account for 80% of sales, the uptake of panty liners and feminine hygiene products has proved sales growth can be achieved by expanding the market.
The vast majority (70%) of purchases take place in grocery multiples, where discounting and own-label sales have become regular fixtures. A significant minority of shoppers (28%) are price-focused, stocking up on special offers and switching brands for the cheapest finds.
Although the number of women in the UK increased between 2004 and 2009, a significant proportion of this growth was among groups falling into the older women demographic. It has therefore not been enough to sustain the growth this sector has experienced in previous decades. However, an estimated 1.8m women of childbearing age have emigrated to the UK between 1996 and 2005.
Innovation is vital for sales growth, but in this sector, many developments, such as more efficient products, mean that women change their protection less frequently; it has therefore failed to translate into volume growth.
As well as preventing and minimising leakage, hygiene and freshness have become central qualities to NPD. A woman's period no longer means that her life is put on hold, and the wide array of feminine hygiene products focus on allowing women to 'carry on as normal'.
Brand owners have capitalised on this message, although the roller-skating, white-jeans-clad women used in the ads of the 80s have been ditched. Tampons and ultra-thin towels tap into this need.
Interest in alternative products has also been growing. Products in this category are more environmentally friendly, such as sponges and reusable cups. While these products remain niche, women are growing more aware of the waste generated by sanitary products, as well as health scares such as toxic shock syndrome and allergic reactions to surfactants - absorbent additives used in tampons.
Research from the British Market Research Bureau suggests that 1% of women have used a reusable menstrual cup. Other brands have tapped into the green mood by offering more environmentally friendly options without expecting women to move away from traditional forms of protection. Natracare, for example, offers biodegradable, disposable tampons as well as towels made from natural fibres.
Many brands aim for the teenage market, to build sustainable brand loyalty via long-term habits and friends' recommendations.
Lil-lets and Tampax, which is owned by Procter & Gamble, are the biggest brands in the tampon market. P&G has put significant adspend into backing its brands, adding Tampax Pearl to the line-up this year and growing the market share of Tampax Compak by 10% since 2007.
P&G also owns the Always towel brand. In 2008 it added a Secure Guard feature, which it claims keeps flow away from the edge by using contours in the pads. It also rebadged its Alldays panty liners under the Always brand to capitalise on its stronger positioning.
Meanwhile, Millie & More's Moxie brand has positioned itself at the premium end of the market with recyclable and reusable tins to hold its products which it claims are 'fashion must-haves'. The imagery of the brand is more in line with cosmetics brands, with stylish packaging meaning the products don't have to be hidden away.
By 2014, the market is predicted to be worth £351m, an 18% rise on 2009, according to Mintel. When inflation is taken into consideration, this equates to a growth of 10%.