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SAD lamps and seasonal affective disorder

Choosing a SAD Lamp

By Joanna Pearl

Article 3 of 3

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Choosing a SAD Lamp

SAD lamps – or SAD lights – can ease the symptoms of seasonal affective disorder. We explain what to consider before buying one.

SAD lamps, also known as SAD lights, are a form of light therapy for people suffering from seasonal affective disorder, or SAD. 

SAD lamps shine very bright, cool light. When this light hits the retina at the back of your eye, it sends nerve signals to parts of your brain, affecting your chemical and hormone levels, and improving mood.

Read on to find out more about SAD lamps, or skip straight to our SAD lamp reviews.

How do SAD lamps work?

Light intensity is measured in 'lux'. To be effective, an SAD lamp needs to emit light of at least 2,500lx – although most light boxes are now 10,000lx. The brighter the light, the shorter the amount of time you will need to sit in front of it.

Research shows that higher light intensity for a shorter time has been as effective as lower light intensity for longer periods.

You'll need to sit with your eyes open about half a metre away from a higher-lux lamp for about half an hour to an hour a day. The light intensity depends on the distance you sit from the lamp, and the manufacturer should specify the lux at given distances.

You can knit, work, watch television and so while you do so, but the light should fall on your face.

There's no conclusive evidence as to the best time of day to use SAD lamps, although early morning is often recommended. It does vary from person to person.

Find out more about seasonal effective disorder.

Is there evidence that light therapy works?

In 2015, Cochrane – a global independent research network – published a systematic review, putting together and evaluating the previous research. Cochrane reviews are regarded as the gold standard for research.

Cochrane concluded that the quality of evidence about whether light therapy prevents winter depression is very low, so it could draw no conclusions. It recommended that patients discuss the various treatment options with their doctor, including the advantages and disadvantages of light therapy and other potential preventative options such as drug treatments, psychological therapies and lifestyle interventions.

Researchers recommended more research comparing light therapy with other options to determine the best treatment for preventing winter depression.

Research is also mixed on whether blue or white light works better on SAD, not least because scientific understanding of how our eyes process light has changed over the last few decades.

Recent research has identified a new blue-light sensitive receptor in the eye that is important for regulating our biological clock. These blue light receptors may regulate the sympathetic nervous system and thus our melatonin levels - but there aren't large scale studies.

An important issue is also whether you will persist with a SAD lamp with blue or white light - which you prefer - as the key to treating winter depression is sticking to your daily regime.

There is also anecdotal reporting from members of the SAD Association that a bigger light, brightening the whole room, boosts mood a little more, but this is not proven, as most research has been done with standard-sized light boxes.

SAD lamp styles and options

Once you've decided to buy an SAD lamp, you'll need to be able to choose the right one for you and your lifestyle. They are not available on the NHS and, with high street prices ranging from around £50 to five times that amount, you'll need to decide which features – the essentials and the 'nice to haves' – are key for you.

Here are our top 10 tips to buying the right SAD lamp for you:

  1. Ensure that the SAD light you choose is a medical device registered with the Medicines and Healthcare products Regulatory Agency (MHRA): this will be stated on the website or box. The MHRA is the government agency responsible for ensuring that medical devices work and are acceptably safe before they are CE marked and placed on the market.
  2. If you buy an SAD lamp – a medical device – for your personal use because of chronic illness or disability, you shouldn't pay VAT. The retailer may require you to complete a written declaration to confirm this.
  3. Lux is the measurement of visible light, and will vary considerably on the distance you are from your light. Choose an SAD light that emits at least 2,500lx, and preferably 10,000lx at a specified distance that suits you. The brighter the light, the shorter the exposure time needed. The manufacturer should provide details of the lux rating for a specified distance and the optimum distance for use, and the Seasonal Affective Disorder Association (SADA) suggests looking for evidence that the lux rating has been independently verified.
  4. Check how long the lamp's instructions recommend you sit in front of the light. It may be tempting to buy a cheaper SAD lamp that requires sitting in front of the light for longer, but committing more time may make it more difficult to keep up your light-therapy regime.
  5. Some SAD lamps have settings to enable you to change the intensity of the light, but you can do this yourself to some extent by moving the light nearer (brighter) or further away, and some would argue that using the maximum setting generally makes sense anyway.
  6. Get the light that's right for your lifestyle. For example, if you travel a lot, you may value a lightweight, portable model with an international adaptor plug and travel bag, or you may want something that will sit discreetly on your desk at work. The light needs to fall on both eyes, so positioning is important. Or you might value a model that uses rechargeable batteries. 
  7. If you've got your mind on other things, you may want a model with a clock and alarm that sounds to remind you to use your light box and let you know when the time is up, but you could just put a reminder on your mobile phone to start your session and keep an eye on the time for when to finish it.
  8. Try it at home. Some manufacturers allow you to try an SAD light for up to a month before you buy. But time it right: for example, it's good to start using an SAD lamp before your seasonal symptoms begin, if you can, although you may derive benefits from starting at a different time. If you're hesitant to make a big purchase straight away, consider hiring or renting one to see if it works for you.
  9. Factor in how long bulbs last for and the cost of replacements. SADA recommends replacing bulbs every three years.
  10. Think about whether looks are important to you and your home. If you find your SAD lamp large and ugly, will you store it away and never take it out again?

Where to buy SAD lamps

SAD lamps are on sale on the high street from retailers including Boots, Argos, John Lewis and Maplin. Or you can search online: websites that sell them include Amazon, Sadbox.co.uk, Sad.uk.com and Sad.org.uk.

High street and online shops sell brands including Beurer, Lumie, Rio, Philips, Lifemax, Litebook, Litepod and the Sad Light Co. There's a wider range available online, and it's worth checking out manufacturers' own websites as prices can be competitive.

What's the difference between SAD lamps and sunrise alarm clocks?

Sunrise alarm clocks (also called light alarm clocks or dawn simulators) slowly increase the light in the room over a period of up to 90 minutes, just before you would normally wake up in the morning. Using one can help reset your daily body clock, and some people also find them helpful in prompting gentler waking in the morning than a traditional alarm.

Sunrise alarm clocks' light isn't as strong as SAD lamps' and, although they may be used in conjunction with SAD lamps for treating symptoms, they are not a medical device and would not be used alone for treating the severe symptoms of SAD.