This Week in Sex is a regular summary of news and research related to sexual behavior, sexuality education, contraception, STIs, and more.

A Mistake That Could Have Consequences (Like Pregnancy)

Pharmaceutical manufacturer Allergan announced this week that it was recalling 170,000 packets of the oral contraceptive Taytulla due to a big packaging problem: The pills with active ingredients and placebos were mixed up.

Most oral contraceptive pills follow a 28-day cycle. These 28 pills come in blister packs and not small, brown bottles with childproof caps because that they have to be taken in the correct order.

The first 21 or 24 days (depending on the brand) of pills contain hormones designed to prevent ovulation. The last four or seven days of pills typically have no active ingredient; they’re just there to keep the user in the habit of taking the pill every day. Pill users typically get their periods during the last few days of their cycle when they are taking the placebo pills and then start a new pack.

One batch of Taytulla, however, had the active pills and the placebo pills reversed so that the placebos were in the slots for the first four days rather than the last four. The placebo pills are a different color than the active pills, but new users might not have known that and even experienced users might not have noticed.

Missing more than two pills with active ingredients can put the user at risk for unintended pregnancy because without the steady dose of hormones, the user may ovulate. Health-care providers usually recommend that anyone who has missed more than two pills should use a backup method of contraception like condoms for at a full week.

Anyone who took Taytulla in the wrong order essentially missed four doses during their first week without knowing it. Allergen said in a statement that anyone concerned about their risk of unintended pregnancy should contact their health-care provider.

Only one lot of Taytulla has been found to have this error. It was a sample pack given to health-care professionals nationwide with the lot number 5620706 and a May 2019 expiration date. The company says that it is notifying patients by letter but that anyone who has one of these packs should return it to their health-care provider. Yes—we realize that’s not much help if you’ve already used it. But check your pill package.

New Concerns About a Very Old Virus 

Earlier this month, a group of more than 60 scientists across the globe drafted an open letter to the World Health Organization (WHO) asking the agency to increase efforts to prevent HTLV-1, an ancient virus (its DNA was found in 1,500-year-old South American mummies) that some experts describe as HIV’s less-aggressive cousin.

The 1980 discovery of the human T-cell leukemia virus type-1 was groundbreaking because it was the first retrovirus (which inserts itself in cells to replicate) ever to be found in humans. The virus is transmitted through bodily fluids, including blood, semen, vaginal secretions, and breast milk. So it can be sexually transmitted or passed from mother to child. HTLV-1 attacks T-cells, an important part of the body’s immune system, making a person susceptible to other illnesses and infections.

If this sounds familiar, it’s because HLVT-1 is very similar to HIV, which was discovered soon after HLVT-1. But HLTV-1 has gotten a lot less attention than its relative because it is not as easily transmissible. Moreover, as many as 90 percent of people who have the virus will remain asymptomatic for their lifetime without treatment. They can spread the virus to others but won’t experience any health issues. Many never know they have it.

For those who do develop symptoms, HTLV-1 can cause neurological issues, eye problems, and bone and joint conditions. But it is best known (and named for) its link to certain types of leukemia (cancer of the blood) and lymphoma (cancer of the lymphatic system). The virus also causes a potentially deadly lung condition called bronchiectasis.

Though prevalence of the virus remains low worldwide, there are certain areas and populations around the world that are disproportionately impacted. A study in a remote community in Australia, for example, found that 40 percent adults were infected. Similarly, there are areas of Southern Japan where 30 to 40 percent of adults over age 50 are infected. The virus is also found in large concentrations in Iran, Jamaica, and Romania. These pockets of infection tend to be in isolated in low-income areas, where residents have limited access to medical care.

The scientists who signed this month’s letter to the WHO believe that we are not doing enough to raise awareness of and prevent HTLV-1. They note 17 prevention strategies that are being used to prevent other bloodborne viruses—ranging from educating the public and health professionals and routine prenatal screening to needle exchange programs—could be useful in preventing HTLV-1. But in most places, those strategies aren’t being used. The letter urges the WHO to “support the promotion of proven effective transmission prevention strategies against one of the most potent human carcinogens.”

Sex and the Sense of Smell

Commercials for Axe Body Spray have been trying to tell us for years that smelling good is the key to getting sex, but new research suggests a different link between odor and orgasm. Researchers at the University of Dresden in Germany found that people with a better sense of smell reported more satisfaction with their sex lives.

The researchers tested participants’ sense of smell by blindfolding them and asking them to identify the scents coming from Sniffin’ Sticks. Participants then completed a survey about their sex lives including questions about desire, performance, and enjoyment.

The results, which were published in the Archives of Sexual Behavior, indicated the people with a greater sense of smell were more likely to enjoy sex. Specifically, “participants with high olfactory sensitivity reported higher pleasantness of sexual activities.” Moreover, women with a stronger sense of smell reported a higher frequency of orgasms during sexual intercourse.

The researchers believe that this is because sex smells, well, sexy. They explain: “The perception of certain body odors such as vaginal fluids, sperm, and sweat seems to enrich the sexual experience.” This may explain why a better sense of smell correlated with better sex but not with increased sexual desire.

It’s worth noting that this study only included 70 people—42 women and 28 men—not enough to draw lasting conclusions. Still, its findings are in line with previous research that has found links between attraction and smell as well as connections between an impaired sense of smell and sexual dissatisfaction.

Apparently, there are some exercises you can do to improve your sense of smell. And you can avoid consuming or using anything with strong tastes and smells like coffee, hard alcohol, hot sauce, or perfume. But before going to this extreme, take some long deep breaths—through your nose—and vow to pay attention to the smells during sex.