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Updated: 2 Mar 2022

SAD lamps: do you really need one and how to buy the best

Find out what the symptoms of SAD are, recommended treatments and what you need to know about SAD lamps and wake-up lights.
Which?Editorial team

As the nights start drawing in, you may be considering a SAD lamp to combat the 'winter blues'. But is it the right solution for you?

A SAD lamp or light box works by replacing the light from sunshine that you’d normally see in the summer. It’s thought that when the light hits the retina at the back of your eye, it may help to tell the brain to make less melatonin, thereby improving mood. However, the evidence for their effectiveness is mixed. 

To help you decide, we explain what the symptoms of seasonal affective disorder (SAD) are, recommended treatments and the pros and cons of SAD lamps, plus top tips for choosing the best SAD lamp if you do wish to buy one.

What are the symptoms of SAD?

It’s not uncommon to suffer from a touch of the ‘winter blues’ when the days are short and we’re plunged into darkness from late afternoon.

However, in the UK, around three people in every 100 suffer from SAD – significant winter depression that can have a big impact on their daily lives. 

There isn’t a test for SAD - instead it's diagnosed by the symptoms, which are similar to depression but usually specific to the winter months. These include low mood, lack of interest and enjoyment in life, low energy, feeling less sociable, feeling irritable, less interest in sex and, in extreme cases, suicidal thoughts. 

SAD symptoms that tend to differentiate it from depression are:

  • Sleeping more Unlike those with non-seasonal depression, people with SAD tend to sleep more rather than less. 
  • Eating more People with SAD might also crave carbohydrate-rich and sweet foods, which can lead to weight gain. 
  • At least two consecutive years of SAD episodes, followed by full remission when the winter season ends. Around two thirds of those who experience it will have it the following year, too.

Who gets SAD? 

Although men can suffer from SAD, three quarters of those affected are women. 

Twin studies show there may be a hereditary element to it, too. SAD usually begins between the ages of 18 and 30, but can develop at any age, although children and older adults don’t tend to suffer from it. 

Mind, the mental health charity, says that people who live near the equator for part of their lives then move further away might also be especially vulnerable to getting SAD. 

About 10% of people with SAD get it during the spring and summer instead, and find that it goes away during the autumn and winter. 

But they usually have trouble sleeping and loss of appetite -  the opposite of what winter sufferers experience.

Causes of SAD

The exact causes of SAD aren’t entirely clear but research has suggested there may be a few things contributing to its development, including: 

  • High melatoninlevels - It’s thought that winter SAD may be partially related to high levels of the hormone melatonin, which is produced in the brain when it’s dark and tells our bodies it’s time to sleep (and is the hormone animals overproduce when they hibernate). However, the exact relationship between melatonin and SAD isn’t clear. 
  • Low serotoninlevels - As well as possibly overproducing melatonin, research at Copenhagen University Hospital has found that people with SAD have lower-than-normal levels of the feelgood hormone, serotonin, in the winter.
  • Body clock disruption - Our bodies use sunlight to time and regulate various important functions, including when we wake up, so it’s thought that lower light levels during the winter months may disrupt our internal body clock and lead to SAD symptoms, including tiredness and depression. Some researchers think it’s because your sleep pattern (sleep phase) when you have SAD starts at a different time. 
  • Other factors - Research by Professor Lance Workman at the University of South Wales in 2018 found that people with brown eyes are more affected by SAD in the winter than people with blue or light-coloured eyes (who produce less melatonin). One theory is that light-coloured eyes let in more light to activate retinal cells at the back of the eye to normalise melatonin levels.

What are the treatments for SAD?

The Royal College of Psychiatrists (RCP) says that self-help will usually be enough to ease mild SAD and even help those with a severe form of the condition. This includes trying measures such as:

Get outside more

‘This is probably the most important point, since SAD is caused by lack of daylight,’ says Prof Workman. 

Exercising outside, such as cycling, walking or running, can really help. 

When you’re indoors, the NHS recommends making your work and home environments as light and airy as possible, and sitting near windows whenever you can. 

If you are working from home more often, or indoors more than usual, it's particularly important, so try and create a routine to ensure you get out in the fresh air and daylight regularly. 

Try light therapy 

If getting out more doesn’t help, you could try a light box, also known as a SAD lamp.

‘Some studies suggest 80% of people with SAD report a significant improvement,’ says Professor Workman. 

The RCP says light therapy tends to work quite quickly so, if it’s going to help, you should notice some improvement in the first week.

Engage in social activities

‘Unfortunately, SAD often makes you want to isolate – but that’s one of the worst things you can do, so it’s a good idea to find a reason for a get-together’ says Prof Workman. This could be outdoors, virtual or otherwise, depending on your current circumstances.

It’s also important to manage your stress levels where possible. If you're struggling we've rounded up some of the mindfulness apps to compare features and prices, and you can also see our guide to accessing counselling services.

See your GP 

If you think you do have SAD and are struggling to cope, it’s best to discuss this with your doctor.

The National Institute for Health and Care Excellence (Nice) says SAD should be treated in the same way as other types of depression.

These include talking treatments such as cognitive behavioural therapy (CBT) or medication such as antidepressants, both of which your doctor can discuss with you. 

The best evidence is for the use of the SSRI medicines sertraline, citalopram or fluoxetine, which help to keep levels of serotonin up. 

For SAD, it’s common to start them in the autumn and to stop them in the spring. 

If SAD recurs, long-term or preventative treatment with an antidepressant called bupropion appears to be backed by strong evidence.

What's the evidence for SAD lamps?

Light therapy is classified as exposure to very bright light for up to four hours a day (average one to two hours) - the light needs to be at least 10 times the intensity of ordinary domestic lighting. 

In 2019, Cochrane – a global independent research network whose reviews are considered the gold standard for research – published a systematic review of light therapy for SAD, putting together and evaluating existing data.

It concluded that the quality of evidence about whether light therapy prevents winter depression is very low. 

However, some studies have found it’s effective for treatment during a SAD phase, especially if used first thing in the morning. 

SADA, the Seasonal Affective Disorder Association, says that light therapy has been shown to be effective in treating up to 85% of diagnosed cases. 

It’s thought that light therapy is best for producing short-term results. This means it may help relieve your symptoms when they occur, but you might still be affected by SAD the following winter. 

When light therapy has been found to help, most people noticed an improvement in their symptoms within a week or so. 

Mind says: ‘The NHS doesn’t provide light therapy because there is currently insufficient evidence to show it works, although some people find it helpful.’ You can find out more on the NHS guide to SAD treatments.

7 tips for buying the best SAD lamp

If you’ve decided that you do want to try a SAD lamp, we’ve rounded up some helpful tips for getting the best one for you. 

SAD lamps are available on the high street from retailers, including Argos, Boots and John Lewis & Partners, or you can search online where there are a number of specialist retailers. 

SAD lamp brands include Beurer, Lifemax, Litebook, Litepod, Lumie, Philips, Rio and the SAD Light Co. 

Before you buy, read through our tips, below:

1 - Check you can use one 

Although most people can use light therapy safely, and reputable light boxes have filters to remove any harmful UV (ultraviolet) rays, exposure to very bright light isn’t suitable for everyone.

This includes:

  • Those with eye damage or a light-sensitive eye condition such as age-related macular degeneration 
  • If you take medication that increases sensitivity to light such as certain antibiotics and antipsychotics 
  • If you take herbal supplement St John’s wort, which is sometimes used to treat mild to moderate depression 
  • Those with skin condition lupus erythematosus, which makes skin especially sensitive to light 
  • Those with bipolar affective disorder as light therapy may trigger some patients. 

Speak to your GP if you're unsure whether a light box is a good idea for you. 

Side effects of light boxes may include headaches, nausea and blurred vision, but the RCP says these tend to be mild. 

2 - Choose a SAD light that’s properly registered

Your purchase should be a medical device that’s registered with the Medicines & Healthcare products Regulatory Agency (MHRA). 

This will be stated on the box or on the product’s website. 

3 - Look for a light that’s strong enough

You need a bright white light emitting at least 2,500 lux (or lx, the units that visible light is measured in) and preferably 10,000 lux to benefit from the effects. 

Research suggests that the most beneficial dose of light is 5,000lx hours daily, which equates to 10,000lx for 30 minutes each day, sitting comfortably around 40cm from the unit. 

However, the light intensity and duration of treatment will depend upon your device and initial response – you may find that as little as 2,500lx works for you. 

There is no known advantage to using blue or bluish SAD lamps over bright white ones.

4 - Use it at the right time of day

The RCP advises using your lamp at breakfast time to help regulate the circadian pattern of melatonin secretion, something that is generally disrupted in SAD sufferers. 

It also recommends that you avoid using it after 5pm because this may make it hard for you to get to sleep. 

Use light therapy consistently on a daily basis, including at weekends, and carry on through the darker months until the days get longer in the spring and summer. 

Keep a regular sleep schedule, too, going to bed and waking up at around the same time.

5 - Buy a good SAD lamp that suits your lifestyle

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. 

Check the manufacturer's instructions for how long you need to use the lamp, to ensure it matches your needs. 

If you’re planning to use it while you’re working out on your home exercise equipment, you might want to buy one you can hang on a wall in front of you. 

A model with a clock and alarm that sounds to remind you to use it, and to alert you to when the time is up may suit you if you’re busy and have your mind on other things.

6 - Try it at home first 

Some manufacturers allow you to try a SAD lamp for up to a month before you buy. 

The other alternative is to consider hiring or renting one to see if it works for you. 

Before you buy, think about whether looks are important to you. 

If you find your SAD lamp large and ugly, you may be tempted to stash it away and get out of the routine of using it. 

If you do buy one, SADA recommends replacing bulbs every three years, so it’s important to factor in the cost of replacements.

7 - Try a sunrise alarm clock

Also known as light alarm clocks or dawn-simulating alarm clocks, these slowly increase the light in the room over a period of up to 90 minutes, just before you’d normally wake up in the morning. 

The RCP says these may be beneficial if you’re finding it hard to wake on winter mornings, helping to gently reset your daily body clock. 

However, the light isn’t as strong as SAD lamps, so although they can be used in conjunction with SAD lamps for treating symptoms, they’re not a medical device and can’t be used alone for treating severe SAD symptoms.

How to use a SAD lamp

 You’ll need to sit with your eyes open about 50cm away from a SAD lamp for about 30 minutes to an hour each day. 

The distance you sit from the lamp depends on its light intensity, and the manufacturer should specify the lux at given distances. 

You can watch TV or work while you do so, but the light should fall on your face.