Can Red Light Therapy Make You Tired?
Red light therapy (RLT) is best known for boosting energy, supporting recovery, improving skin health, and even stimulating hair growth. At ReGen Rooms in Leamington Spa, our clients often book sessions in the NovoTHOR full-body bed to recharge and recover from training, work, or stress.
But one question comes up time and time again: “Can red light therapy make you tired?”
The short answer: red light therapy doesn’t drain your energy. In fact, it helps your cells create more. But because it calms the nervous system and encourages deep recovery, some people feel sleepy after a session — especially in the evening.
At ReGen Rooms in Leamington Spa, we regularly see clients from across Warwickshire — including athletes, Warwick University students, and busy professionals from Coventry — who use red light therapy to improve recovery and sleep.
Let’s dive into the science, why it happens, and what it means for you.
How Red Light Therapy Works in the Body
Red light therapy uses wavelengths between 600–900nm to penetrate the skin and underlying tissues. These wavelengths are absorbed by the mitochondria — the tiny “power plants” inside your cells.
When light hits the mitochondria, they produce more adenosine triphosphate (ATP), which fuels nearly every process in the body. The result?
Better circulation
Faster repair and regeneration
Lower inflammation
More efficient cellular function
CGI medical illustration of red light therapy penetrating skin, mitochondria absorbing light, producing ATP, boosting repair and hair growth.
So if RLT is literally helping your body make more energy, why do some people feel tired after treatment?
Why Some People Feel Tired After Red Light Therapy
1. Nervous System Reset
Red light therapy activates the parasympathetic nervous system — also known as the “rest and digest” state. Most people spend the majority of their day in sympathetic “fight or flight” mode, fuelled by stress, stimulants, or constant multitasking. This keeps cortisol levels elevated and the body on high alert, which in turn makes it harder to relax, recover, or sleep properly. When you step into the NovoTHOR red light therapy bed at ReGen Rooms, the wavelengths of light encourage a rapid shift into parasympathetic dominance. Breathing slows, heart rate steadies, and muscles begin to release stored tension. For many clients, this sudden change feels like a wave of calm or even drowsiness, not because their energy is being drained but because their body is finally given permission to rest. This effect is one reason RLT pairs so well with our other recovery services like contrast therapy and the infrared sauna, both of which also help regulate stress responses and promote deep relaxation.
2. Melatonin & Circadian Rhythm
Light exposure is one of the strongest regulators of the circadian rhythm, your internal 24-hour clock that governs sleep and wakefulness. Blue light from screens and overhead LEDs is known to suppress melatonin, the hormone that tells your brain it’s time to sleep, which is why so many people struggle with rest in the digital age. Red and near-infrared wavelengths, by contrast, do not interfere with melatonin in the same way; in fact, they may help restore natural balance and improve your sleep–wake cycle¹. At ReGen Rooms, we often hear from clients who notice they fall asleep faster and stay asleep longer after a series of sessions. Scientific research backs this up, with a controlled trial on athletes showing that daily red light therapy improved both sleep quality and endurance performance². For anyone experiencing sleep disruption, combining red light therapy with good sleep hygiene practices — such as avoiding screens at night, or pairing sessions with our infrared sauna to promote circulation and relaxation — can create powerful results.
3. Cellular Repair & Recovery
One of the reasons red light therapy feels so restorative is its ability to enhance ATP production — the energy currency of your cells. Every process in the body, from muscle contraction to skin repair, depends on ATP. When RLT increases ATP, the body prioritises repair and regeneration, focusing energy where it’s most needed. Clients often describe the post-session sensation as similar to what they feel after a massage or yoga practice — a heavy relaxation that comes from tissues actively healing. Inflammation reduces, circulation improves, and the nervous system interprets this as a cue to slow down³. This “healing fatigue” is not a negative side effect but rather a sign that the therapy is working as intended. Over time, consistent use leads to faster recovery, higher energy levels, and better performance. Many athletes at ReGen Rooms combine red light sessions with PEMF therapy or oxygen training to enhance cellular repair even further, creating a synergistic recovery protocol.
4. Timing of Your Session
When you choose to schedule your session can shape how you feel afterwards. Morning or midday sessions usually leave clients feeling energised and alert, as the ATP boost and circulation improvements line up with the body’s natural rhythm of productivity. This makes red light therapy a popular pre-work or pre-training choice for athletes and professionals. Evening sessions, on the other hand, can amplify the body’s wind-down process, making them ideal for those struggling with insomnia, stress, or difficulty switching off at night. At ReGen Rooms in Leamington Spa, many clients specifically book evening appointments because they notice the therapy helps them drift into deeper, more restorative sleep. To maximise results, we often recommend combining red light therapy with other relaxation-focused treatments such as the Sunlighten infrared sauna or contrast therapy, depending on your goals. By tailoring the timing of your sessions, you can use red light therapy to either boost your daytime energy or support your body’s natural rest cycle.
How Red Light Therapy Compares to Other Recovery Treatments
Some clients ask how the post-session feeling from red light therapy compares to other recovery methods. Each therapy influences the body differently:
Infrared sauna — The heat stress from an infrared sauna often makes people feel physically tired straight afterwards. The body is working to regulate temperature and flush toxins through sweat, which can leave you ready to rest. Many of our clients use the sauna in the evening to help them unwind before bed.
PEMF therapy — Pulsed Electromagnetic Field therapy works more directly on the nervous system, calming overactive signals and reducing stress. Clients often describe a sense of deep relaxation or mental quietness, rather than sleepiness.
Red light therapy — By contrast, red light therapy delivers a balance. Some people feel drowsy immediately after treatment as their nervous system switches into rest-and-repair mode, but the long-term effect is usually more energy, better sleep quality, and faster recovery.
Each treatment has its place, and many clients at ReGen Rooms combine them into a personalised plan depending on whether their focus is relaxation, recovery, or boosting energy.
Red Light Therapy, Fatigue & Sleep
It’s important to stress that feeling tired after red light therapy is not a negative side effect. In fact, most people notice benefits such as:
Improved sleep quality — deeper, more restorative sleep cycles
Reduced stress-related fatigue — less mental exhaustion
Faster recovery — from workouts, injuries, or chronic inflammation
Daytime energy boost — after consistent sessions
In other words, while you may feel sleepy for an hour or two afterwards, the long-term effect is usually higher energy and better rest overall.
-
For most people, any drowsiness only lasts an hour or two after a session. It’s more like a post-yoga or post-massage calm than real fatigue. Over time, the long-term effect is improved daytime energy, not ongoing tiredness.
-
Yes. Feeling relaxed or a little sleepy is a normal response and shows your body is shifting into rest-and-repair mode. It isn’t harmful and usually means the nervous system is responding well to treatment.
-
It depends on your goals. Morning or midday sessions tend to leave clients feeling more energised, while evening sessions can help support deeper, more restorative sleep. Many ReGen Rooms clients book later appointments specifically to wind down after a busy day.
How to Maximise Your Results
If you’re worried about post-session drowsiness, here are a few ways to make RLT work best for you:
Book morning or midday sessions if you want an energising effect.
Book evening sessions if you struggle with insomnia or poor sleep quality.
Stay hydrated — water supports improved circulation and nutrient delivery.
Pair with wellness habits like stretching, meditation, or sauna for a stronger relaxation response.
Listen to your body — if you feel like resting, allow yourself the downtime.
Beyond Energy: The Whole-Body Benefits
Although many people first try RLT for recovery or skin health, clients quickly notice wider benefits that extend far beyond energy and sleep.
Skin quality — Red light stimulates collagen and elastin, improving tone, texture, and resilience.
Muscle and joint health — By lowering inflammation, RLT helps relieve stiffness and soreness after training or long workdays.
Stress management — Consistent use helps regulate the nervous system, reducing anxiety and promoting calm.
Circulation — Better micro-circulation delivers oxygen and nutrients more efficiently, fuelling long-term energy.
Hair Growth -
This is why we see such a wide range of clients at ReGen Rooms - from athletes and professionals to Warwick University students managing study stress.
Why Choose ReGen Rooms in Leamington Spa
At ReGen Rooms, we’ve invested in the NovoTHOR XL full-body red light therapy bed, widely regarded as the gold standard in photobiomodulation. Unlike handheld devices or small panels, it ensures complete, even coverage — giving you consistent results every time.
We’re based in central Leamington Spa, close to landmarks like the Royal Pump Rooms and the River Leam. Our clients come from across Warwickshire, including athletes, students, and professionals looking to recover, recharge, and perform at their best.
Sessions last 15–20 minutes, and you can choose a time of day that suits your goals: morning for an energy boost, or evening for better sleep.
Final Thoughts
So, can red light therapy make you tired? Not in the sense of draining energy - but it can trigger a deep relaxation response that makes some people feel sleepy afterwards. Over time, most clients experience the opposite effect: better sleep quality, faster recovery, and higher daytime energy.
Want to experience the benefits for yourself?
Book your red light therapy session at ReGen Rooms in Leamington Spa, Warwickshire today and discover how it can transform your energy, recovery, and sleep.
👉 Book Your Red Light Therapy Session
References
LeGates TA, Fernandez DC, Hattar S. Light as a central modulator of circadian rhythms, sleep and affect. Nat Rev Neurosci. 2014;15(7):443-54. doi:10.1038/nrn3743.
Zhao J, Tian Y, Nie J, Xu J, Liu D. Red light and the sleep quality of Chinese female basketball players during training. J Athl Train. 2012;47(6):673-8. doi:10.4085/1062-6050-47.6.08.
Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophys. 2017;4(3):337-361. doi:10.3934/biophy.2017.3.337.