• L-Theanine 100mg (SunTheanine)
  • L-Theanine 100mg (SunTheanine)
  • L-Theanine 100mg (SunTheanine)
  • L-Theanine 100mg (SunTheanine)
  • L-Theanine 100mg (SunTheanine)
  • L-Theanine 100mg (SunTheanine)

L-Theanine (SunTheanine®) Amino Acid

£ 15.25

£0.25 / capsule
(1) Reviews
100mg | 60 capsules

Mood-promoting effects that may effectively lower mental and physical stress

L-Theanine - An Amino Acid that promotes a calm and relaxed effect, supports positive mood, and improves mental focus and attention

The L-Theanine found in this product is from SunTheanine®, the only 100% pure form of L-Theanine, that has been proven to be safe and efficacious.  

Theanine is an amino acid that has shown to increase serotonin and dopamine levels in the brain. These brain chemicals are commonly known as ‘feel good’ neurotransmitters, and as such, they help to boost mood, decrease anxiety, and promote relaxation but without any drowsiness. L-Theanine also supports brain health by improving focus and attention and boosting cognition.

Theanine is an amino acid derived from herbal green tea and has calming and mood-promoting effects that can effectively lower mental and physical stress, and may also help with sleep disturbances. It has been seen to enhance the activity of an enzyme that breaks down beta-amyloid protein - which has been associated with the development of Alzheimer’s disease. Theanine may also help to lower blood pressure.

As with most amino acid supplements, your body generally needs vitamin B6 (pyridoxine) as a cofactor to ensure correct amino acid metabolism.


L-Theanine 100mg – From SunTheanine®, is a 100% pure, patented source of L-Theanine.

SunTheanine® is the only pure L-theanine which has 40 internationally recognised patents, and which has been scientifically proven in clinical studies to be safe and efficacious.

Independent laboratory analysis confirms that various other products on the marketplace, claiming to contain L-theanine, are, instead, half L-theanine and half D-theanine (the mirror image of L-theanine), which has not been scientifically evaluated in published studies.

  • Most amino acids come in two forms; D- or L- (such as L-tyrosine or D -tyrosine). The D-amino acid is a mirror image of the L- amino acid -  in other words the D- form is a backward image. 
  • Both can be taken. However, the L-form is preferable as it is the exact image of the amino acid in its natural form found in the body. The L- form is considered the more effective for overall human health.

As a dietary supplement, adults take one tablet, one to three times daily between meals or as directed by a health professional.

Store in a cool, dry place, away from direct light.

Do not exceed the recommended daily dose.

Keep out of reach of young children.

Children, pregnant women, and women who are breastfeeding should consult their doctor before use.

Nutritional supplements should not replace a varied and balanced diet and a healthy lifestyle.

Check with simultaneous intake of medicines with your physician or healthcare professional. No long-term use without professional advice.

L-Theanine 100mg - From SunTheanine®, a 100% pure, patented source of L-Theanine.

Other Ingredients:

Cellulose, water (vegetarian capsules), cellulose, magnesium stearate and silica.

Free from: Sugar, salt, dairy, yeast, wheat, gluten, soy, corn, preservatives, artificial colours or flavours.

Nathan PJ, Lu K, Gray M, Oliver C. The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent. J Herb Pharmacother. 2006;6(2):21-30

Akiko Higashiyama, Hla Hla Htay, Makoto Ozekib, Lekh R. Juneja, Mahendra P. Kapoor. Effects of l-theanine on attention and reaction time response. Journal of Functional Foods. Volume 3, Issue 3, July 2011, Pages 171-178

Nobre AC, Rao A, Owen GN. L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pac J Clin Nutr. 2008;17 Suppl 1:167-8

Kakuda T. Neuroprotective effects of the green tea components theanine and catechins.cBiol Pharm Bull. 2002 Dec;25(12):1513-8

Kakuda T. Neuroprotective effects of theanine and its preventive effects on cognitive dysfunction. Pharmacol Res. 2011 Aug;64(2):162-8

Kimura K, Ozeki M, Juneja LR, Ohira H. L-Theanine reduces psychological and physiological stress responses. Biol Psychol. 2007 Jan;74(1):39-45

Kim TI, Lee YK, Park SG, Choi IS, Ban JO, Park HK, Nam SY, Yun YW, Han SB, Oh KW, Hong JT. Theanine, an amino acid in green tea, attenuates beta-amyloid-induced cognitive dysfunction and neurotoxicity: reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-kappaB pathways. Free Radic Biol Med. 2009 Dec 1;47(11):1601-10

Mon 31st Jul 2017

Great product, saw really good reviews elsewhere so glad to be able to use it.

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