Our circadian rhythm is the internal 24-hour cycle that governs almost every process in the body — from sleep, hormone release, and digestion to metabolism, immunity, and mood. When aligned, this biological clock helps us feel energised in the morning, sleepy at night, and balanced throughout the day. It even influences how our gut microbiome behaves, which in turn shapes our immunity, mood, and metabolism (Thaiss et al., 2016).
However, when disrupted — through irregular sleep, mistimed eating, chronic stress, or stimulants like caffeine — this delicate rhythm can shift. The result is often fragmented sleep, hormonal imbalance, metabolic dysregulation, and lower overall resilience.
☕ How Coffee Affects Your Internal Clock
Caffeine is a powerful stimulant — but it doesn’t just make you feel awake. It directly interacts with your body’s timing mechanisms:
- A landmark study showed that consuming caffeine equivalent to a double espresso 3 hours before bedtime delayed the onset of melatonin by around 40 minutes, shifting the body’s internal clock later into the night (Burke et al., 2015).
- Caffeine has been shown to lengthen the circadian period in both human cells and animal models, affecting the oscillation of clock genes (Oike et al., 2015).
- Even daytime caffeine consumption alters sleep architecture and circadian dynamics, reducing slow-wave sleep and shifting wake promotion patterns (Landolt, 2015).
- Observational data show that people who consume coffee later in the day have significantly reduced melatonin peaks and more frequent circadian disruption compared to morning-only drinkers (Kim et al., 2025).
This matters because when circadian signals are consistently delayed or dampened, it doesn’t just affect sleep — it can ripple into digestion, hormone cycles, mood, and inflammation.
🦠 Gut Rhythms and Circadian Health
Our gut microbes follow their own daily rhythms, which are tightly linked to our body’s internal clock (Thaiss et al., 2016). Disrupting circadian timing — whether through mistimed meals, irregular sleep, or stimulant use — can desynchronise the microbiome, contributing to metabolic issues and inflammation (Zarrinpar et al., 2016).
Research also shows that gut microbes influence our stress responses and hormonal balance in a circadian manner (Zhou et al., 2024). Sleep disruption, in turn, can blunt microbial rhythms and amplify inflammation (Anderson et al., 2020).
🌱 Nous & Soma: Energy Without Circadian Disruption
At Nous & Soma, we believe energy shouldn’t come at the expense of your body’s natural timing. That’s why our blends are crafted without high-dose caffeine. Instead, we use functional botanicals and plant nutrients that support steady energy, gut balance, and hormonal harmony without shifting your internal clock.
Our formulations aim to enhance focus and vitality within your body’s natural rhythm, helping you feel energised during the day — and restful at night.
🧬 References
- Burke TM et al., Sci Transl Med, 2015;7(305):305ra146. doi:10.1126/scitranslmed.aac5125
- Oike H et al., Cell Rep, 2015;13(6):1254-1264. doi:10.1016/j.celrep.2015.09.066
- Landolt HP et al., Neurosci Biobehav Rev, 2015;55:1-13. doi:10.1016/j.neubiorev.2015.04.002
- Kim J et al., Eur Heart J, 2025;46(8):749-760. doi:10.1093/eurheartj/ehac801
- Thaiss CA et al., Cell, 2016;159(5):1025-1036. doi:10.1016/j.cell.2014.11.003
- Zarrinpar A et al., Cell Metab, 2016;20(6):1006-1017.
- Zhou X et al., Cell Metab, 2024;36(4):650-662.
- Anderson JR et al., Curr Opin Microbiol, 2020;55:1-6.
