Poor sleep while taking medication? This could be why.

By Sander | Crystal Clarity

In our HRV data, we notice a striking pattern: people who take corticosteroid medication shortly before going to bed show sleep quality that is 2 to 20 percent worse than on other nights. This is not a scientific study, but an observation in our own data that sparked my curiosity — reason enough to explore the scientific literature.

What exactly do we measure?

We measure sleep recovery using HRV, heart rate variability. HRV is the variation in time between successive heartbeats. Higher HRV during sleep is associated with better physical and mental recovery. It is not an absolute measure, but one of the signals we include in our assessments to understand how well someone recharges during the night.

What does the science say?

The pattern we observe in our data is confirmed by published scientific research.

Corticosteroids reduce HRV

A double-blind crossover study (Philippi et al., 2024) demonstrated in women that acute cortisol administration significantly reduces HRV. Two prospective observational studies in pregnant women (Bester et al., 2023 and 2024) showed that betamethasone, a commonly used corticosteroid, increases heart rate within 24 hours and significantly lowers parasympathetically related HRV indices. Notably, this effect disappeared within three to four days after the last dose.

Corticosteroids increase the risk of sleep problems

A meta-analysis published in JAMA Network Open (Lima et al., 2025) analysed 45 randomised studies involving 6,470 participants. The conclusion: short-term use of systemic corticosteroids significantly increases the risk of sleep problems, with 15 additional cases per 1,000 users compared to the control group. The quality of evidence was rated as moderate, which in scientific literature is considered a solid basis for clinical conclusions.

The evidence is not straightforward

Honesty requires us to also acknowledge the conflicting findings. Not all corticosteroids have the same effect.

A study in children with Duchenne muscular dystrophy (Dias et al., 2021) showed that prednisone improved HRV to levels comparable to healthy controls, while deflazacort did not. This illustrates that the type of corticosteroid makes a meaningful difference.

Intranasal corticosteroids, a different route of administration with a fundamentally different mechanism than systemic use, improved self-reported sleep quality in people with allergic rhinitis (Tabata et al., 2024). This effect was likely indirect, driven by reduced nasal symptoms rather than a direct influence on sleep architecture. Objective sleep measures such as the Epworth Sleepiness Scale showed no significant effect in the same meta-analysis.

The conclusion is therefore nuanced: the type of corticosteroid, the dose, and the route of administration all make a considerable difference to the effect on sleep and HRV.

What do we see in our own data?

Among people who, in consultation with their doctor, took their medication earlier in the day, we measured improved sleep quality and HRV during sleep. This is consistent with what is known about the biological action of corticosteroids: the body has its own cortisol rhythm, with a natural peak early in the morning. Taking corticosteroids late in the day can disrupt this rhythm.

Who is this relevant for?

Sleeping well and feeling rested? Then there is no reason to act on this.

This is only relevant if you are taking corticosteroids and are also experiencing sleep problems or persistent fatigue. In that case, it is worth discussing the timing of your medication with your doctor. The timing of medication is a medical decision, and not something to change on your own.

References

• Philippi et al. (2024). Cortisol administration reduces heart rate variability in women. Psychoneuroendocrinology.

• Bester et al. (2023 and 2024). Betamethasone and maternal heart rate variability. Prospective observational studies.

• Lima et al. (2025). Adverse Events Following Short-Course Systemic Corticosteroids Among Children and Adolescents. JAMA Network Open. https://consensus.app/papers/details/dd6c749df2765a509c6f44a21c665535/

• Dias et al. (2021). Corticosteroid type and HRV in Duchenne muscular dystrophy. Pilot study.

• Tabata et al. (2024). Intranasal corticosteroids and sleep quality in allergic rhinitis. Meta-analysis of 18 RCTs.