It is recommended that, in anal sex, condoms should be used with plenty of silicone- or water-based lubricant. During vaginal sex, a woman produces natural lubricating fluids, but these may not be enough for safer condom use. The amount of fluid a woman produces changes throughout the menstrual cycle, and is influenced by several factors. It is quite natural for women to need additional lubrication for comfort as well as for safer sex.

Until recently all water-based lubricants apart from those containing nonxynol-9 were regarded as safe. New research amongst comparatively small groups of people unveiled at the 2010 International Microbicides Conference suggests that some water-based lubricants may in fact facilitate HIV transmission – see below. However more research is needed before a definitive statement can be made on which water-based lubricants are safe, and which less so.

One piece of advice that still stands is that using oil-based substances, such as Crisco or cooking oil, as lubricants with condoms is not effective. Oils and greases weaken condoms drastically and dangerously within minutes. Often an oil-covered condom will split during sex and users may not realise it is burst or torn until after the event. Users should be advised that if nothing else is to hand saliva is preferable as a lubricant to oil-based ones. Some kind of lubricant is always preferable, as ‘dry sex’ increases friction, puts extra strain on the condom, and is likely to cause trauma in the receptive partner.

Doubts about some water-based lubricants

Thirty years of safer-sex advice were thrown into confusion at the 2010 International Microbicides Conference when a survey of lubricant use amongst a group of women and gay men found that those who used lubricants for anal sex were three times more likely to acquire gonorrhoea, chlamydia or syphilis than those who used none.1 HIV incidence was not measured as the group studied was too small for this to be a meaningful datum.

The effect was independent of the number of partners people had or how many times they had sex, and was also independent of whether they used condoms or not.

Researcher Pamina Gorbach of the University of California, Los Angeles, stressed that these results came from a small survey and that her study was not powered to analyse the risk of various different lubricants.

However, an accompanying study by Charlene Dezzutti and Janet Russo of the University of Pittsburgh did find that some lubricants created more cellular damage than others.2

Gorbach’s survey was part of the U19 rectal microbicide research initiative funded by the US National Institutes of Health. Between October 2006 and December 2008, 879 men and women from the U19 programme completed computer-assisted self-interviews for the researchers about their sexual behaviour and were tested for rectal STIs – gonorrhoea, chlamydia and syphilis.

In order to include enough women who had had anal sex, half the interview group consisted of women who had had receptive anal intercourse (RAI) at least once in the last year, whereas gay men were only included if they had had RAI in the last month.

Just under half of the people interviewed (421 people, 47.6%) reported having had receptive anal sex within these criteria: 229 men having had it in the last month and 192 women in the last year. Of these, 302 completed the behavioural survey and all STI tests; the remaining data concern this group.

The group was 58% male and was a somewhat older group than many sex surveys, with a median age of about 40; 51% were African-American and the average socioeconomic status was poor, with 21% of the group classing themselves as homeless and 35% as disabled.

Three-quarters of the group (230 people) said they had used a lubricant during the last time they had had receptive anal intercourse. Lubricant use was less common in African-Americans (38.5%) and Hispanic people (58%). More HIV-positive people used a lubricant than HIV-negative people.

People used various kinds of lubricant: 67% had used a water-based one such as KY Jelly, 28% a silicone-based lubricant, 17% an oil-based substance such as Crisco, and 6% a numbing lubricant designed to deaden sensation.

One in 12 group members tested positive for a rectal STI (5.6% of women and 10.2% of men); only chlamydia and gonorrhoea were included in the analysis as syphilis is often transmitted orally.

Over one in nine (11.7%) of lubricant users were positive for a rectal STI compared with one in 22 (4.5%) who did not use lubricant: this was statistically significant (p=<0.05).

More than two-thirds (68%) of people diagnosed with rectal gonorrhoea and/or chlamydia had used a lubricant compared with a third of people who had not used a lube.

In multivariate analysis, using a lubricant was associated with a more than threefold greater risk of acquiring an STI (relative risk 3.15, 95% CI, 1.23 to 8.04). This was after controlling for number of partners, frequency of sex, condom use, gender and HIV status. In other words, lubricant use was not a surrogate marker for other risk behaviours but appeared to pose an independent risk. When syphilis was included in the analysis, the association of STIs with lubricant use was even stronger.

“What’s our take home message here?” Gorbach was asked. She said that her message would be that people should choose their lubricating substance carefully. Lubricants were not regulated like medicines: they were classed as ‘medical devices’ and did not have to undergo stringent safety testing. Many had ingredients that were “not friendly” to the cells lining the rectum.

To underline this, another study (Russo) tested for toxicity six lubricants that can be bought over the counter in the USA. These were five water-based lubricants (Astroglide, Elbow Grease, ID Glide, KY Jelly and PRÉ vaginal lubricant) and one silicone-based one (Wet Platinum).

The physical properties of each lubricant were measured. Four lubricants (Astroglide, KY Jelly, ID Glide and Elbow Grease) were strongly hyperosmolar. This means that they would cause water to diffuse out of the cells lining the rectum into the rectum itself.

The lubes were tested on ‘friendly’ bacteria that are part of the normal vaginal flora. Astroglide killed off one species of Lactobacillus, and KY Jelly, which contains the disinfectant clorhexidine, killed all species.

The four hyperosmolar lubricants stripped off the epithelium (outer layer) of cells from rectal tissue. In contrast, PRÉ and Wet Platinum caused relatively little damage. Astroglide caused almost as much damage as nonoxynol-9, the spermicide whose use has been shown to increase susceptibility to HIV.

As members of the audience commented, these studies do not imply that people should be advised not to use lubricant in anal sex, as this can cause trauma in itself. However, there is clearly an urgent need to conduct further research into sexual lubes, distinguish between harmful and harmless ones, and probably introduce more stringent safety checks for them before licensing them for over-the-counter sale.

Nonoxynol-9 spermicidal lubricant

Some condoms may be advertised as being 'spermicidally lubricated'. A spermicide is a chemical substance which is used with other forms of contraception (for example, with a diaphragm). The only spermicide available in the UK is nonoxynol-9, also known as N-9.

Problems with N-9 were revealed when it was investigated as a possible microbicide. It was chosen for research on the basis of laboratory findings that it disrupted HIV and other STIs, even at very low doses, and because it was already in widespread use, including in lubricants for condoms. Animal studies confirmed that N-9 protects female monkeys against HIV-related viruses.3,4

Unfortunately, N-9 causes damage to human tissue, leading to inflammation and ulceration, which is dose-related.5 It was nonetheless hoped that low-dose N-9 products, used vaginally, might be able to protect against HIV without causing excess inflammation.

However, the results of extensive clinical trials carried out on N-9 as a microbicide were clear-cut: N-9 increased HIV transmission to women who were at high risk of HIV when they used the product frequently, and appeared to have no protective effect either against HIV or other STIs when used less frequently. The most important evidence that N-9 is ineffective – or has a negative value – as a microbicide came from a randomised, placebo-controlled trial of a low-dose N-9 vaginal gel, COL-1492, that reported in 2002.6

This study enrolled 775 female sex workers in four countries: Benin, Ivory Coast, South Africa and Thailand, all of whom were supplied with condoms and encouraged to use them, as well as having enhanced access to diagnosis and treatment of STIs. Among these women, a further distinction was made between frequent users and less frequent users, with a threshold mean value of 3.5 uses per day.

The findings were that among less frequent users, HIV rates were not significantly different between N-9 and placebo groups. However, among more frequent users, HIV rates among N-9 users were twice the rate among placebo users. There was no effect of N-9 on rates of gonorrhoea or chlamydia infection.

A meta-analysis of eight randomised controlled trials of N-9 used vaginally assessed new HIV infections, new episodes of various STIs, and genital lesions. Comparing women using N-9 with women using a placebo or taking no treatment, there were no statistically significant differences in the risk of infection with HIV, gonorrhoea, chlamydia, cervical infection, trichomoniasis, bacterial vaginosis or candidiasis. However genital lesions were more common in the N-9 group (risk ratio 1.18, 95% confidence interval 1.02 to 1.36).7

Research into N-9 as a rectal microbicide was minimal and where it occurred, produced even more worrying results than in trials as a vaginal microbicide: the use of N-9 caused the rectal lining to slough off in both mice and humans, prompting a warning about the popular use of N-9-containing lubricants during anal sex. Far from protecting against HIV and other viral infections, N-9 leaves the rectum more susceptible to it.8

As a result of these studies, there is a consensus among organisations concerned with sexual and reproductive health that nonoxynol-9 has no role in preventing HIV and other STIs, and its use should be discouraged by anyone perceived to be at risk. At the same time, there continues to be a role for spermicides containing N-9, as readily available but moderately effective non-hormonal contraceptives, for women and couples who are at very low risk of HIV or other STIs.

It is particularly important that products containing N-9 should not be used for anal sex.

There has been resistance from condom manufacturers to calls to remove 'spermicidal lubrication' with N-9 from their products, as they perceive that it meets a demand for 'extra safety' from some users. Expert opinion is that the low dose of N-9 in that lubricant does not add to their contraceptive value and might even distract women from the need for emergency back-up contraception if condoms fail. Durex has now removed spermicidal lubrication from all its condoms, but some brands still contain it.


  1. Gorbach PM et al. Rectal lubricant use and risk for rectal STI. 2010 International Microbicides Conference, Pittsburgh, abstract 348, 2010
  2. Russo J et al. Safety and anti-HIV activity of over-the-counter lubricant gels. 2010 International Microbicides Conference, Pittsburgh, abstract 347, 2010
  3. Miller C et al. The effect of contraceptives containing nonoxynol-9 on the genital transmission of simian immunodeficiency virus in rhesus macaques. Fertility and Sterility 57:1126-1128, 1992
  4. Weber J et al. 'Chemical condoms' for the prevention of HIV infection: evaluation of novel agents against SHIV 89.6 PD in vitro and in vivo. AIDS 15:1563-1568, 2001
  5. Niruthisard S et al. The effects of frequent nonoxynol-9 use on the vaginal and cervical mucosa. Sexually Transmitted Diseases 18:176-179, 1991
  6. Van Damme L et al. Effectiveness of COL-1492, a nonoxynol-9 vaginal gel, on HIV-1 transmission in female sex workers: a randomised controlled trial. Lancet 360:971-977, 2002
  7. Wilson D et al. Nonoxynol-9 spermicide for prevention of vaginally acquired HIV and other sexually transmitted infections: systematic review and meta-analysis of randomised controlled trials including more than 5000 women. The Lancet Infectious Diseases 2: 613-617, 2002
  8. Phillips DM Safety of rectal lubricants. Presentation to the International Rectal Microbicide Working Group, Chicago, 27 February, 2006
This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.
Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

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