Pill that sapped the pope's power

This well-researched, wide-ranging and highly readable book will deservedly become the definitive study of the subject for the foreseeable future. The first accounts of the development of the pill tended to be rather heroic ones of the Americans - notably Gregory Pincus, Carl Djerassi and John Rock - who pioneered its development, emphasising how they overcame sexual and religious prejudice. More recently, feminists have given the story a more critical turn. They have highlighted the use of women from third-world countries as guinea pigs in clinical trials; argued that the pill had not yet been adequately tested when first put on the market; and implied that a key motivation among the pill's enthusiasts lay in the male desire to control female fertility - and to give men trouble-free sexual pleasure.

In these and other respects, Lara Marks, who already has fine histories of motherhood in London to her credit, provides the wider picture and a balanced perspective. She shows that, spurred by the development of endocrinology, the search for a non-barrier method of contraception occupied many medical scientists, pharmaceuticals firms and campaigners for women on both sides of the Atlantic from early in the 20th century. The crucial breakthrough came around mid-century, with the advent of ways of manufacturing large amounts of hormones economically.

Marks argues convincingly that, though the quantity and quality of clinical trials would not meet today's ethical criteria, by mid-century standards, the pill had been more systematically tested than most drugs - hardly surprising given that the companies marketing it were deeply apprehensive of a hostile reception and bad publicity. And Marks argues plausibly that third-world testing was in some measure forced on the pill's developers by the presence in American law of an array of statutes outlawing the promotion of contraception - opponents or rivals could easily have taken them to court.

From the time of its introduction in the late 1950s, some women thought the pill the best thing that had ever happened to them ("a dream come true" - or, as one English mother declared, "like winning the pools"). Especially among the poor, it finally freed wives from the dread of another unwanted pregnancy; it gave women welcome control over their own fertility, and for many turned sex into something to be enjoyed rather than endured. Other users were not impressed. It produced unpleasant side-effects; it sparked justifiable concern that it produced thrombosis and cancer: and it fed chauvinist expectations (in the "swinging Sixties") that women were there to service men on demand.

Marks avoids deifying or demonising the pill. She underlines the wide spectrum of responses among users and commentators at large, and shrewdly highlights the significance of that range. For the pill was unique in its time in being the first "designer drug", taken not to cure a dire disease but to enhance a lifestyle. At least in the first world, women knew very well that the choice - to take it or leave it - was theirs, and they have fully availed themselves of that choice. Uptake of the pill became user-led, and the medical profession was largely forced to fall into line. Confuting early champions who confidently expected it to supersede all other forms of contraception (was it not mess-free and 100 per cent effective?), the pill took its place as just one among many birth-control options. These days, most first-world women use it at some time or other (especially early in their sexual career), but few rely on it exclusively.

Indeed, some of the most original and insightful sections of Sexual Chemistry are Marks's discussions of complexes of factors that have determined its adoption, both individually and socially. Contrary to the hopes of its pioneers, many of whom had their eye on global overpopulation, third-world use has remained very patchy: the pill is simply too expensive. Uptake was low even in some parts of the first world, Japan for instance (why? - condom manufacturers and abortion-performing gynaecologists effectively lobbied governments). And much has hinged on the structure of national agencies (doctors have tended to dish out the pill more readily than birth-control clinics) and governments' willingness to foot the bill. It is an ironic reflection of developments in the National Health Service, Marks notes, that the pill was originally one of the few prescription items that you had to pay for, whereas today it is one of the few that is free.

Marks assesses papal opposition in a chapter titled "Divisive device". Quite a few of the early advocates of the pill were devout Roman Catholics, notably John Rock. And they, along with certain liberal theologians mainly in Belgium and the Netherlands, were hopeful that, precisely because the pill was not a barrier method of regulating fertility but replicated natural hormonal responses, it would prove acceptable to the Vatican. Such hopes were dashed by Pope Paul VI's encyclical Humanae Vitae of 1968. Yet, Marks argues, that "divisive device" should not be seen as the reactionary pronouncement of a diehard, valiantly if vainly turning his back on the modern world - and on the legitimate grievances of women. Rather it was the dithering response of a feeble old man fearful of departing from traditional teachings. These days, Catholics resort to the pill about as much as others, but Humanae Vitae has proved a milestone in the undermining of papal authority.

Skilfully combining medical, social and feminist history, Sexual Chemistry is a model study of the impact, of one of the fundamental pharmacological innovations of the previous century. Indeed, it points to a key transformation in the wider world of medicine: the move from an exclusive or prime concern with combating disease to a broader (and often consumer-driven) concern with aspirations for the body.

Roy Porter was formerly professor in the social history of medicine, Wellcome Trust Centre for the History of Medicine, University College, London.