We have all celebrated the come back of Sunita Williams from the nine-month long ISS mission. But did you know that for the longest women astronauts were not sent into space or sent on more extended missions because of menstruation. However, it was not until Sally Ride, who became the first woman to menstruate in space became famous for her tampons.

This of course came with a set of challenges and figuring out on how many tampons would she need. Or how would she dispose them or the cost and weight of it. However, the big question is, how do women handle their period in space. How does menstruation work in microgravity?

Menstruation In Microgravity

While it is a common guess for many to think that in space, it becomes a retrograde menstruation, which means the blood flows back and could cause damage too. However, this is not the case. The female reproductive system is actually immune to the lack of gravity.

There are two options in how astronauts manage their period in space. They can either choose to delay period by taking pills or just deal with it as and when it comes.

There are waste-disposal facilities on board the international space station or the ISS that can handle human blood. However, it had not always been designed this way. Another challenge for women having their period is the added weight and the calculations of taking items like tampons and sanitary napkins.

The astronauts at NASA also undergo individual assessments tailored to their needs, mission duration and physiology. There are protocols too that allow for several choices, and individual treatment selected for any particular astronaut is a private matter between the astronaut and the flight surgeon.

However, the reality is that most women actually opt for contraceptives and put their periods on hold. This happens both during the preparation and during the spaceflight. However, no research has yet been done on long-term use of contraceptives in space. What we do know is that it can be consumed for long-term on earth.

Things Were Not Always That Easy

Like mentioned before, women were not sent on space missions thinking of retrograde menstruation. Furthermore, in 1964, researchers from the Women in Space Program suggested that putting "temperamental psychophysiologic human" which means hormonal women together with a "complicated machine" was a bad idea. While this was without any evidence, such biases have further hindered women and their achievement in the space.

However, it was the 1971 NASA report that pointed out that there may be place for women in space.

The Kanas and Fedderson's 1971 report went on to state: Information regarding women during periods of stress is scanty. This lack, plus previously mentioned problems will make it difficult for a woman to be a member of the first long-duration space missions. However, it is just as unlikely to think that women cannot adapt to space. Initial exploration parties are historically composed of men, for various cultural and social reasons. Once space exploration by men has been successfully accomplished, then women will follow. In preparation for this, more information should be compiled regarding the physiology and psychology of women under stressful situations.

The Centers for Disease Control and Prevention (CDC) released three reports on Thursday that highlighted the clusters of medetomidine-related cases in Chicago, Philadelphia, and Pittsburgh. These reports have raised alarm about the growing presence of this drug in street opioids and the potential complications it brings to treatment and recovery.

What Is Medetomidine?

As per the American College of Medical Toxicology (ACMT), it is an alpha-2 agonist, similar to clonidine and xylazine, that is used clinically as a sedative and analgesic. It is categorized as an NPS due to its novelty in use. The CDC in its Morbidity and Mortality Weekly Report notes that it is a canine veterinary agent used for its anesthetic and analgesic properties.

However, the National Library of Medicine's study titled Classics in Chemical Neuroscience: Medetomidine has noted that this drug "has recently been detected in the illicit drug supply alongside fentanyl, xylazine, cocaine, and heroin, producing pronounced sedative effective that are not reversed by naloxone."

As per the latest CDC report released on May 1, twelve confirmed and 26 probable cases of medetomidine-involved overdose occurred in Chicago. Fentanyl was present in all blood specimens and drug samples that tested positive for medetomidine.

It was first identified in North America’s illicit opioid market in 2022, medetomidine is now showing up more frequently in mixtures with synthetic opioids—particularly fentanyl, the drug driving most overdose deaths in the U.S.

Why Is This Worrisome?

In May 2023, Chicago officials noticed a spike in overdose cases where naloxone—the standard overdose-reversal medication—did not work as expected. After investigation, the city's health department confirmed 12 cases involving medetomidine, with over 160 more suspected or probable cases, including one potential death. This marks the largest known medetomidine cluster to date.

The two other CDC reports focused on medetomidine withdrawal. In Philadelphia, testing revealed medetomidine in 72% of illegal opioid samples collected in late 2023, overtaking xylazine in frequency. Patients exposed to medetomidine experienced a distinctive type of drug withdrawal that didn’t respond to usual medications for fentanyl or xylazine. However, a related medication called dexmedetomidine showed some success in managing symptoms.

Pittsburgh reported 10 similar cases around the same time, suggesting the issue is not isolated to one area but may be spreading through regional drug supplies.

Why Does It Matter?

The presence of sedatives like medetomidine in illicit opioids creates several public health challenges:

Reduced effectiveness of naloxone: Standard treatment protocols for overdoses may not work when sedatives are involved, increasing the risk of death.

Complicated withdrawals: The addition of new, unregulated substances alters the withdrawal process, often making it harder to treat.

Lack of awareness and testing: Many emergency responders and clinics do not routinely test for medetomidine, which could delay proper care.

This development adds a new layer to the already complex U.S. opioid crisis. As drug suppliers continue to mix opioids with a variety of sedatives and adulterants, health officials face an evolving battle. Experts stress the importance of broader toxicology screening, continued research, and expanding the availability of alternative treatments like dexmedetomidine.

While medetomidine isn’t yet as widespread as fentanyl or xylazine, its growing presence in cities like Chicago, Philadelphia, and Pittsburgh points to a potentially dangerous trend—one that will require urgent attention from both medical professionals and policymakers.

Receiving a vaccine booster in the same arm as the first dose triggers a faster and stronger immune response and helps the body build protection faster, a new study from Australian scientists has revealed. The findings could help improve vaccine strategies and may eventually lead to vaccines that need fewer boosters. The study was published in the journal Cell and finds that the immune system responds more quickly when both doses are given in the same arm.

Why Will It Work?

Researchers have reasoned that getting jabbed in the same arm works better because immune cells in nearby lymph nodes, which are the body's infection-fighting hubs, become "primed" after the first shot. When the booster arrives in the same spot, these cells spring into action and help produce stronger antibodies. "This is a fundamental discovery in how the immune system organises itself to respond better to external threats," said the study's co-senior author Tri Phan, director of the Precision Immunology Program at the Garvan Institute.

Researchers discovered this effect first in mice, then confirmed it in a clinical study involving 30 people who received the Pfizer COVID-19 vaccine. Those who had both doses in the same arm developed faster and more effective protection, especially against COVID-19 variants like Delta and Omicron. While both groups ended up with similar antibody levels after four weeks, the same-arm group gained protection more quickly, a potential game-changer during pandemic outbreaks.

"If you've had your COVID jabs in different arms, don't worry, our research shows that over time the difference in protection diminishes," said the study's co-senior author, Mee Ling Munier from the Kirby Institute.

How Do Vaccines Work?

The immune system has a wonderful layered system of defences, and when it comes to vaccines, two major defenses are activated. One of them is antibodies, which are proteins in the blood. Then you have something called cell-mediated immunity, which involves cells, usually T lymphocytes. You almost always get both. From a regulatory point of view, you often measure antibodies in people and basically know how effective a vaccine is in a population.

Microplastics pose a danger to the heart. While there is enough evidence to show that they clog arteries and exacerbate the risk of stroke, recent research has found that these teeny particles of plastic can trigger cardiovascular diseases. It is estimated that chemicals in plastic were linked to nearly 350,000 heart disease deaths across the world in 2018. Adding to that, is this study published in the journal eBioMedicine, which estimated that roughly 13 per cent of cardiovascular deaths among 55- to 64-year-olds worldwide that year could be attributed to phthalates.

Where Are Phthalates are esters of phthalic acids, which are added to plastics to increase their flexibility, transparency, durability, and longevity. They are found in personal care products like shampoos and lotions as well as in food containers and packaging. It is also possible to injest them through food, absorb them through skin from products containing them or breathe them from dust.

Some studies have shown an association between phthalates and cardiovascular disease, but there isn’t strong evidence to show that the chemicals directly cause heart issues, said Sung Kyun Park, a professor of epidemiology and environmental sciences at the University of Michigan School of Public Health. However, there is enough evidence that states that phthalates increase the risk of metabolic disorders like obesity and Type 2 diabetes, which can cause cardiovascular disease. One way phthalates may do this is by increasing oxidative stress—cell and tissue damage that happens when there are too many unstable molecules in the body—and by promoting inflammation.

Microplastics: Explained

Microplastics are extremely small particles—often less than five millimetres in size—created when larger pieces of plastic break down. They can enter the human body in multiple ways: through the air we breathe, the food we eat, and even skin contact. An even smaller subset, known as nanoplastics, measures under 1,000 nanometers and is completely invisible to the naked eye. Because of their minuscule size, these particles can infiltrate tissues, organs, and potentially disrupt biological functions.

One Simple Way To Mitigate Risk Of Microplastics

Amid growing concerns about microplastic contamination, especially in drinking water, scientists have been working on practical ways to mitigate exposure. In 2024, a research team from Guangzhou Medical Centre made a breakthrough. They discovered that a common household activity—boiling water—can significantly reduce microplastic content in tap water.

According to the team, combining boiling with basic filtration can remove up to 90% of nanoplastic and microplastic particles (NMPs) from household water. However, the method’s effectiveness varied depending on the type of water used. In areas where tap water contains higher mineral content, commonly referred to as "hard water," the technique proved especially efficient.

The secret lies in limescale. As hard water is heated, it forms limescale—a chalky white substance—which appears to create a sticky layer that traps microplastic fragments. Researchers found this natural process enhanced the removal of plastic particles from water, offering a practical and affordable solution for most households.

While more research is needed to fully understand the long-term health effects of microplastics, early evidence suggests they may be more dangerous than previously thought—especially for cardiovascular health.