L-Theanine Benefits: Better Sleep and Less Stress

L-theanine benefits include promotion of relaxation, stress reduction, restful sleep, and increased concentration. It is an amino acid that is found in both green and black tea. It is also found as a stand alone supplement and in combination formulas designed to promote sleep and relaxation.

Many of my patients have benefited from adding L-theanine to their lifestyle routine to help with stress, anxiety, and mental focus.

L-Theanine Benefits

L-theanine is an amino acid found primarily in green and black tea. It is also found in some mushrooms and can be taken in supplement form. People use it primarily to ease stress, anxiety, and promote sleep.

Anxiety and Stress Reduction

The benefits of L-theanine and its effects are more than anecdotal. In fact, research¹ has shown that using L-theanine can help reduce stress and anxiety.

A study published in The Journal of Clinical Psychology² found a benefit in anxiety reduction when using 400 mg L-theanine in addition to ongoing treatment in those with schizophrenia.

Other studies³ have found that L-theanine promotes relaxation without causing drowsiness.

It’s important to note that while there have been studies showing benefits of L-theanine for mental health, it is not a replacement for medication.

Stress and Blood Pressure

Are you someone who experiences an increase in blood pressure during stressful events? L-theanine may be beneficial in combating these effects of stress.

In one study⁴ it was found that L-theanine helped ease the effects of stress on blood pressure in people who experience elevations in response to physiological and mental stress. The same study also found that it helped ease anxiety in these situations.

Improved Sleep

L-theanine has been found in the research to improve sleep in both human and animal studies. In one randomized controlled trial⁵ it was found that those taking L-theanine had fewer sleep disturbances and fell asleep more quickly compared to the placebo group. Those using L-theanine also had improved mental clarity.

In another study⁶ it was found that L-theanine and GABA had a synergistic effect on both sleep quality and duration.

Is L-Theanine Good for Stress?

There’s an undeniable stress epidemic, and it’s affecting us ladies more than men. A recent study⁷ found that American and Western European women feel stressed almost twice as often as men.

Women under 35 are even more likely to struggle with stress and anxiety. One study found that women tend to rate life events⁸ as more negative and less controllable than men, even though there was no difference in the number of life events experienced in the previous two years. The same study showed that women also had more physical signs of stress than men. Another study found that women tend to feel a heightened sense of responsibility and guilt around work and family issues⁹, which could contribute to increased stress.

Are Women More Susceptible To Stress?

Research¹⁰ has shown that men and women cope with stress differently. Men tend to take a problem-solving approach to stress, while women tend to dwell on stressful events, amplifying the impact these events have on their mood.

Research¹¹ also suggests that hormonal changes set women up for stress. Fluctuating estrogen and progesterone levels during menstruation, pregnancy, perimenopause, and menopause could make women more prone to anxiety.

I’ve discussed previously how hormonal imbalances can trigger anxiety. But the truth is, stress and the anxiety it creates can also drive hormone imbalances. It leads to a vicious cycle that’s difficult for many women to break free from without support.

Stress and Your Hormones

When you’re stressed, your adrenal glands start pumping out a hormone called cortisol. Cortisol can be really useful in life or death situations. It increases your blood sugar¹², giving you the energy you need to either fight the threat you face or flee from it. It slows down other body processes to direct everything you’ve got to the threat at hand.

To give you that extra boost of energy, cortisol stops other bodily functions that aren’t essential in an emergency situation, like immune response, digestion, and reproduction¹³. This is no big deal if the stress is temporary. But if you have high levels of stress daily, it becomes a serious problem that impacts your fertility and your health.

Chronic stress can interfere with your body making the sex hormones estrogen and progesterone, which can stop reproduction.

Beyond your fertility, high cortisol levels weaken your immune system, put you at risk for diabetes¹⁴, and contribute to obesity¹⁵. High cortisol is also tied to mood problems¹⁶ and, of course, anxiety.

Regardless of where your problem starts — with stress or with your hormones — it eventually becomes a vicious cycle. Stress continues to drive your hormonal imbalance, and your hormonal imbalance makes you feel more stressed.

How Can L-Theanine Help Reduce Stress?

L-theanine is an amino acid found in green tea, black tea, and a specific mushroom species¹⁷. Even though it’s one of the rarest amino acids found in food, it’s one of the most useful for fighting stress.

In one randomised, double-blind, placebo-controlled crossover study¹⁸ it was found that L-theanine lowered the cortisol response.

It also boosts levels of GABA¹⁹, a neurotransmitter that promotes relaxation and sleep.

L-theanine triggers alpha brain waves²⁰ as well. Alpha brain waves occur when you’re relaxed but still awake, like when you meditate or daydream. They make you feel relaxed but not sedated, which may explain why L-theanine has been shown to decrease anxiety while increasing alertness²¹.

L-Theanine Side Effects

In general, L-theanine is regarded as safe to consume or supplement with as there are no known side effects.

However, consuming large amounts of green tea in order to take in more L-theanine can be a different story. High green tea consumption can lead to an upset stomach, irritability, and agitation.

In addition, if you are pregnant or breastfeeding, you should be mindful of your food intake, specifically your caffeine intake.

How to Take L-Theanine

Green and black tea are the best naturally-occurring dietary sources of L-theanine. But you’d have to drink quite a bit of tea (like 10 cups or more per day²²) to match the L-theanine doses typically used in studies. As noted above, there can also be adverse effects from consuming high doses of caffeine.

That’s why many people opt for L-theanine supplements instead. Typical dosages of L-theanine range from 100 to 400 mg per day, which is similar to what’s been used successfully and safely in studies showing benefits to reducing stress and supporting sleep.

L-theanine doesn’t have many side effects, but it’s always a good idea to talk to your doctor before starting new supplements, especially if you have low blood pressure or if you’re pregnant or nursing.

Our Product with L-Theanine

Adrenal Calm: We lovingly refer to this as the “chill pill” because it promotes a state of calm and helps take the edge off of stress. This formula is a synergistic blend of 200 mg of L-theanine, adaptogenic herbs like Ashwaghandha, nourishing B Vitamins, and Phosphatidylserine, this formulation supports restful sleep and cortisol balance. When evening cortisol keeps you tossing and turning, Adrenal Calm is the perfect ally. You can learn more about Adrenal Calm here. The typical dose is 3 caps with dinner.

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About The Author

Dr. Jolene Brighten

Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.