L-Theanine is an
amino acid that helps promote a mild, restful, relaxed state with minimal daytime
sedation. L-Theanine has much fewer side effects than other commonly used relaxing agents.
For better sleep at night, consider Good Night Rx.
•
Suntheanine, a patented form of L Theanine, is a trademark of Taiyo
International, Inc.
• Promotes relaxation and stress reduction
L-Theanine Supplement Facts
L Theanine - 100 mg
(Suntheanine brand)
How L Theanine may work
Orally administered l theanine is absorbed through the intestinal tract and hydrolyzed in
the liver to glutamic acid and ethylamine. Ethylamine,
a molecule that primes the response of an immune system element called the gamma-delta T
cell, which may protect against infection.
L Theanine and Stress
l-Theanine reduces psychological and physiological stress responses.
Biol Psychol. 2006 Aug 21; Nagoya University Department of Psychology,
Chikusa-ku, Nagoya, 464-8601, Japan.
Because the characteristics of l-Theanine suggest that it may influence
psychological and physiological states under stress, the present study examined
these possible effects in a laboratory setting using a mental arithmetic task as
an acute stressor. Twelve participants underwent four separate trials: one in
which they took l-Theanine at the start of an experimental procedure, one in
which they took l-Theanine midway, and two control trials in which they either
took a placebo or nothing. The experimental sessions were performed by
double-blind, and the order of them was counterbalanced. The results showed that
l-Theanine intake resulted in a reduction in the heart rate (HR) and salivary
immunoglobulin A (s-IgA) responses to an acute stress task relative to the
placebo control condition. Moreover, analyses of heart rate variability
indicated that the reductions in HR and s-IgA were likely attributable to an
attenuation of sympathetic nervous activation. Thus, it was suggested that the
oral intake of l-Theanine could cause anti-stress effects via the inhibition of
cortical neuron excitation.
L Theanine research shows
L-Theanine (delta-glutamylethylamide) is one of the predominant
amino acids ordinarily found in green tea, and historically has been used as a
relaxing agent.
L-Theanine might be useful for preventing ischemic neuronal damage.
L-Theanine increases the idarubicin-induced antitumor activity and ameliorates its
toxicities.
L-Theanine summary
Human research with l-theanine is limited, and hence the clinical usefulness of theanine is
not clear to me at this time. However, some users report that l-theanine helps them
relax and helps with sleep. See
insomnia cures if you would like to sleep better and deeper.
L Theanine side effects
I have not come across any research regarding the side effect profile of
l theanine side effects. In my experience, dosages greater than 300 mg of l-theanine cause a
side effect of transient lightheadedness. It is possible that L-theanine side
effects regarding drowsiness could be elicited when combined with kava, 5-HTP,
passion flower, valerian, or other herbs and nutrients that have a sedative
effect. Rat studies have not found any l-theanine side effects of concern.
Theanine and blood pressure
Q. So I really want to start trying l-theanine for my
life-long anxiety problems, as it is one of the only suppliments or drugs I have
found that is touted for being helpful for anxiety, and yet not making the user
feel dopey and tired. My concern is that I have low blood pressure (so much so
that the nurses who check me always think they've done it wrong), and I have
read that l-theanine lowers blood pressure. So my question is this: Does l-theanine
lower blood pressure, or regulate it? Should a person with low blood pressure
avoid this suppliment, or does it only lower blood pressure when it needs
lowering? Is the lowering of blood pressure that comes along with this
suppliment significant enough to worry about, even if it will take down the
blood pressure of an already low person?
A. Not enough human studies have been done to determine the role of
l-theanine in influencing blood pressure in those who have normal or low blood
pressure. We could only find one human that showed theanine prevents the rise in
blood pressure from caffeine intake. Very, very large theanine dosages given to
rats lowers their blood pressure. Since the effects of herbs and amino acids are
dose dependent, one option is to take half of a 100 mg capsule and monitor one's
blood pressure over the next few hours to see how it affects you and then base
future dosages on the initial response. Have approval by your doctor.
Toxicity and Safety of L Theanine
A 13-week dietary toxicity and toxicokinetic study with l-theanine in rats.
Food Chem Toxicol. 2006 Jul;44(7):1158-66. Borzelleca JF, Peters D,
Hall W. Department of Pharmacology and Toxicology, Medical College of Virginia,
Virginia Commonwealth University, Richmond, VA
This study was conducted to evaluate the safety of l-theanine ( Suntheanine )
when administered as a dietary admixture to male and female rats at
concentrations providing doses of 0, 1500, 3000 or 4000 mg/kg body weight per
day for 13 weeks. There were no consistent, statistically significant
treatment-related adverse effects on behavior, morbidity, mortality, body
weight, food consumption and efficiency, clinical chemistry, hematology, or
urinalysis. There were no consistent treatment-related L theanine side effects
in gross pathology, organ weights or ratios or histopathology. The increased
incidence of renal tubular cell adenomas in high-dose females only were not
consistent with the characteristics of a renal carcinogen (due to early onset
and low number of animals affected) but were more consistent with a genetic
predisposition than with direct organ toxicity. The
no-observed-adverse-effect-level was 4000 mg/kg bw/day, the highest Suntheanine
dose tested.
Theanine Research Update
Anti-obesity effects of three major components of green tea, catechins, caffeine
and theanine, in mice.
In Vivo. 2004 Jan-Feb;18(1):55-62.
To elucidate the anti-obesity effects of three major components of green tea,
catechins, caffeine and theanine, female mice were fed on diets containing
2% green tea powder and diets containing 0.3% catechins, 0.05% caffeine and
0.03% theanine, which correspond, respectively, to their concentrations in a 2%
green tea powder diet, singly and in combination for 16 weeks. Body weight and
food intake were determined monthly during this period, kidneys, adrenals,
liver, spleen, brain, pituitary and intraperitoneal adipose tissues (IPAT) were
weighed and lipid levels in the serum and liver were measured at the end of this
period. The body weight increase and weight of IPAT were significantly reduced
by the diets containing green tea, caffeine, theanine, caffeine + catechins,
caffeine + theanine and caffeine + catechins + theanine. Noticeably, the IPAT
weight decreased by 76.8% in the caffeine + catechins compared to the control
group. Serum concentrations of triglycerides and non-esterified fatty acids
(NEFA) were decreased by green tea, catechins and theanine. Moreover, caffeine +
catechins, caffeine + theanine and caffeine + catechins + theanine also
decreased NEFA in the serum. The triglyceride level in the liver was significantly reduced
by catechins and catechins + theanine in comparison with the control. These
results indicated that at least caffeine and theanine were responsible for the
suppressive effect of green tea powder on body weight increase and fat
accumulation. Moreover, it was shown that catechins and caffeine were
synergistic in anti-obesity activities. I theanine side effects
Theanine Emails
Q. I'm using L-theaning and i think it just saved my life,
it helped me with social anxiety, concentration, sleep or just feeling good. i
had several panic attacks and now when i discovered this i just take it when i
feel like it's starting and it causing it to completely disappear. BUT, but
question is, I know all the benzodiazepines (Valium, Xanax) are causing an
increase in the GABA, but they are extramly addictive and dangerous. Is L-theanine
addictive too? Sometime if i take like 300mg of L-theanine a day I start to feel
depressed after like 6-8 hours, could it have something to do with it? I've been asking this a couple of psychiatrists and they just say they
don't know anything about alternative medicine and they don't think any amino
acids could cause any addiction
A. We don't know enough about long term theanine use,
hence it is difficult to say whether long term l theanine use causes low mood.
However, as with most supplements, taking breaks is useful and other
anti-anxiety agents can be substituted, such as 5-htp, kava, ashwagandha,
passionflower, etc. I am not aware of any serious cases of addiction to amino
acids. A lower dose of l-theanine, such as 200 mg, may not cause the low mood
after several hours. Or, using l-theanine only in the evening could make a
difference.
Q. I've been taking L-theanine for insomnia for
about a month and it seems to really help. My question is this: If there
are immune stimulating effects
from L-theanine, could this amino acid possibly be bad for auto-immune
diseases?
A. We have not seen any studies to indicate L theanine to have a
major influence on the immune system. However, it often takes years of
studies to determine the full impact of a supplement on the immune system,
and thus far such studies regarding L theanine and the immune system have
not been done.
Q. i just finished reading your page about
yohimbe and there is one thing not mentioned there which i am concerned
about. i am planning to take l-theanine or theanine for anxiety, maybe i
will take 200mg or so in the morning, can i take yohimbe at noon time or
in the afternoon? is it ok? Thanks and i would like like u to know that u
have a wonderful website, physicanformulas.com sells good products, too
A. We have not seen any research with the combination of yohimbe
and theanine, but if your doctor approves you can start with low dosages
of each to see how your body reacts. Each person reacts differently to
herbs and supplements, and to combinations of supplements.
Q. I have been taking L-theanine occasionally and
I've noticed that the two times I've taken it fairly close to going to bed
I've had insomnia! I'm taking it in an attempt to lower my creeping-up
blood pressure with the hope that I'll feel calmer and less stressed and
that this will help my labile hypertension to stabalize. I would
appreciate any information you might have about whether l theanine could
be causing the insomnia and how it might be used for lowering blood
pressure.
A. In some people l theanine may cause a slight alertness, and this
may also depend if there are other supplements added to the l theanine
product. See our page on hypertension for suggestions on blood pressure
control.
Q. Absolutely love your site. I send it to
everybody I know! What do you know about L-Theanine? A doctor recommends l
theanine for anxiety. Just wondering what your thoughts were.
A. There are herbs and other nutrients more potent than l theanine
for anxiety.
Q. Could you tell me please if taking L Theanine
supplement, which is supposedly better absorbed than GABA, if L Theanine
is more helpful for sleep than GABA.
A. In my opinion, L theanine is more potent than GABA. Good Night
Rx is more potent than L theanine for sleep.
Q. How nice to find a website that has solid
information on more natural alternatives to pharmaceuticals! Hope you will
be around a long time. I have been reading about L-Theanine and wondered
if you have any information on whether it has been used to treat ADHD. My
7 year old son has been diagnosed with ADHD and we do not want to put him
on stimulant medication.
A. I searched Medline for the keywords theanine ADHD and could not
find any studies regarding the treatment of ADHD with a l theanine
supplement. Sometimes the only way to tell if a supplement will work is by
trial and error. Theanine appears to be a safe amino acid, at least in the
short term. I am not aware of long term human studies using l theanine
supplements.
See also tryptophan serotonin website since tryptophan and 5-HTP supplement increase serotonin and help induce sleep.
Tanacetum parthenium,
also known as feverfew plant, grows widely across Europe and North America. The
leaves of Tanacetum parthenium have been historically used for the therapy of fever and more recently migraine headaches.
Terminalia
arjuna has antioxidant properties and may be clinically helpful in cardiovascular
health.
This theanine supplement page was last updated in 2008.