Why your body loses its rhythm in November – and what science says about it

It's 4:30 p.m. and getting dark outside. You're still at the office, staring at your screen, and you can feel your body telling you: time for bed. Your boss sees things differently – three more hours, then you can go home. At 10 p.m., you're lying wide awake in bed, your mind racing, wondering why your sleep-wake cycle is completely out of whack.

Welcome to November. The sun sets as early as 4:30 p.m., it's still dark when you get up in the morning – and yet work and everyday life still demand peak performance. What sounds like an individual problem is actually a biological phenomenon that affects many city dwellers. Your circadian rhythm – your body's internal clock – is thrown off by the changing light conditions.

The science behind your disrupted sleep

Your body has an internal clock that is primarily synchronized by light exposure. When light hits your retina, signals are sent to the suprachiasmatic nucleus in your brain—essentially the headquarters of your biological rhythms. This system has functioned according to the same principle for millennia: bright light in the morning signals "day," while darkness in the evening triggers melatonin production and prepares your body for sleep.

The November problem: When it's dark in the morning and gets dark early in the evening, your body loses its natural rhythm. The production of melatonin – the hormone that signals it's time to sleep – is no longer stimulated at the right time. That alone would be challenging enough. But in urban environments, the situation is dramatically exacerbated by artificial light.

Scientific studies show that even two hours of exposure to blue light in the evening (at a wavelength of approximately 460 nm) can significantly suppress melatonin production and delay your circadian rhythm. Harvard researchers have found that blue light exposure shifts circadian rhythms twice as much as green light of comparable brightness.

This is where the urban factor comes into play: Your office is brightly lit – but with the wrong light spectrum. Smartphones and screens emit blue light well into the night. Streetlights shine through your bedroom window. Your circadian rhythm literally no longer knows whether it's day or night.

A recent study from 2024 delivers striking figures: People with the lowest mortality risks were exposed to virtually no light at night – especially between 2:30 and 3:00 a.m., the most sensitive phase for the circadian rhythm. Conversely, the study showed that people with bright days and dark nights can live up to five years longer than those with the opposite pattern. Five years of life expectancy – through better light timing.

Three evidence-based strategies for better sleep

1. Use morning light as a time cue

Morning light exposure is the strongest factor in synchronizing your circadian rhythm. Research shows that 30 minutes of exposure to bright light (between 2,500 and 10,000 lux) in the morning can advance the circadian phase and stabilize the sleep-wake cycle.

For comparison: Even a cloudy sky provides around 10,000 lux, while a typical living room lamp only reaches 300 lux. The difference is massive – and your body notices it. Interestingly, studies also show that people who are exposed to more natural light during the day are significantly less sensitive to artificial lighting in the evening.

In practical terms, this means you should spend 15-30 minutes in daylight within the first two hours after waking up – ideally without sunglasses, so the light reaches your retina directly. If this isn't possible due to your commute or schedule, a daylight lamp with 10,000 lux for 20-30 minutes while having breakfast can be a scientifically sound alternative.

2. Take evening light reduction seriously

Research is clear on this point: Blue light in the evening significantly inhibits melatonin secretion. Light in the wavelength range of 460-480 nm is particularly problematic – precisely the spectrum that modern LED screens emit most intensely.

A study by Brigham and Women's Hospital in Boston has shown that ordinary room light of less than 200 lux can reduce melatonin production by about 90 minutes. This means your living room lamp is sabotaging your sleep hours before you even think about going to bed.

The solution isn't to sit in the dark after 6 p.m., but to consciously manage your light exposure. Activate blue light filters on all devices as soon as the sun sets. Even more effective are blue light glasses, which are specially designed to filter out the problematic wavelengths. Ideally, screens should be completely avoided in the last hour before bedtime – although this is often difficult to implement in reality.

3. Create optimal bedroom conditions

Research data shows that even minimal light exposure during sleep can reduce melatonin production by up to 50 percent. A 2018 study demonstrated that even low light levels of 5-10 lux with closed eyes can trigger a circadian response. This means that even the small LED light of your alarm clock or the glow of your TV's standby indicator can disrupt your sleep.

Therefore, blackout curtains or sleep masks are not luxury items, but scientifically proven aids for restful sleep. Temperature also plays an important role – the optimal range is between 16 and 18 degrees Celsius. Within this temperature range, your body can most efficiently lower its core temperature at night, which is necessary for deep sleep.

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Support through targeted supplementation

During the darker months, it can be beneficial to give your body some extra support. GABA (gamma-aminobutyric acid) is the most important inhibitory neurotransmitter in the central nervous system and plays a key role in the transition to rest. Scientific reviews from 2024 confirm that GABA can contribute to the normal function of the nervous system and support the body's natural shutdown process.


Studies have shown that lavender extract can reduce nighttime rumination and improve subjective sleep quality – a common problem for people living in urban environments with high cognitive load.


URVI Night Support was specially developed for people who struggle with light pollution and irregular sleep patterns in urban environments. The formula with GABA and lavender extract helps your body wind down despite adverse conditions. Taking it 30-60 minutes before bedtime gives your body time to transition into sleep mode.

The difference between knowledge and action

November doesn't have to be your sleepless season. With evidence-based strategies – morning light exposure, evening light reduction, and optimal sleep conditions – you can stabilize your circadian rhythm, even if the light conditions are working against you.

The challenge isn't knowing this information, but actually putting it into practice. But that's precisely where your power lies: you have more control over your sleep-wake cycle than you might think. Every small adjustment – ​​whether it's a morning walk, dimmed lighting in the evening, or total darkness in the bedroom – adds up to measurable improvements.

Your body wants to sleep. The city makes it difficult. But you now know the scientific levers to restore balance.

Important NOTE

This article is for informational purposes only and does not replace medical advice. If you have any health concerns or are unsure about supplementation, please consult a physician or nutritionist. The effectiveness of dietary supplements may vary from individual to individual.

Sources

Blume, C., Garbazza, C., & Spitschan, M. (2019). Effects of light on human circadian rhythms, sleep and mood.
Skeldon, A.C., et al. (2023). Associations between light exposure and sleep timing and sleepiness while awake.
Cajochen, C., et al. (2006). Systematic review of light exposure impact on human circadian rhythm.
Harvard Health Publishing. (2024). Blue light has a dark side.
Cho, CH, et al. (2018). Impact of exposure to dim light at night on sleep.