Every batch of Gentle Hours is tested for identity, potency, heavy metals, and microbials before it ships. Here's the certificate of analysis for the batch in your bottle.
LabYanling Natural Hygiene · GMP
Batch5DB01036S
Manufactured30 Jul 2025
Expires29 Jul 2027
CoA issued22 Oct 2025
Potency · per capsule
L-theanine spec 90–120 mg103.9 mg
Magnesium spec 45–62.5 mg48.62 mg
Heavy metals
Lead (Pb) limit 10.0 mg/kg<0.02 mg/kg
Arsenic (As) limit 5.0 mg/kg<0.02 mg/kg
Cadmium (Cd) limit 0.3 mg/kg<0.02 mg/kg
Mercury (Hg) limit 0.5 mg/kg<0.02 mg/kg
Microbial
Total aerobic count<10 cfu/g
Yeast & mould<10 cfu/g
Bile-tolerant Gram-neg<10 cfu/g
E. coliAbsent / 1 g
S. aureusAbsent / 1 g
Salmonella sp.Absent / 10 g
Physical
Moisture content max 7%2.4%
Disintegration ≤30 minPass
Uniformity of weight 90–110% avgConform
CapsuleWhite vegetable, size 00
Issued by Goh Guek Ling · MJMM0966 · Yanling Natural Hygiene Sdn Bhd (321810-D)
Every claim on the page traces back to peer-reviewed research. Here are the studies behind the science.
L-theanine · Alpha waves
The effects of L-theanine on alpha-band oscillatory brain activity
Gomez-Ramirez et al. · 2007 · Neuropharmacology
EEG recordings showed significantly elevated alpha activity within 30–40 min of 250mg dose.
L-theanine, a natural constituent in tea, and its effect on mental state
Nobre, Rao, Owen · 2008 · Asia Pacific J Clin Nutrition
Alpha-wave induction at 50–200mg; effect present within 45 min, sustained 2+ hrs.
L-theanine · Stress response
Effects of L-theanine on stress response and cognitive function
Hidese et al. · 2019 · Nutrients
Randomized trial, 200mg/day × 4 weeks. Reduced stress scores, improved verbal fluency.
Magnesium · Dietary gap
Suboptimal magnesium status in the United States: NHANES analysis
Rosanoff, Weaver, Rude · 2012 · Nutrition Reviews
~45% of US adults consume below EAR for magnesium. Source of the 45% stat on this page.
Magnesium · Bisglycinate absorption
Bioavailability of magnesium amino acid chelate vs. oxide
Schuette, Lashner, Janghorbani · 1994 · JPEN
Chelated magnesium absorbed 4× more efficiently than oxide form.
Where this comes from, who we buy it from, and how it gets to you.
Origin
Shizuoka Prefecture, Japan
L-theanine extracted from Camellia sinensis — the same green tea species used for matcha and sencha. Our supplier's farms have been in the same family for four generations.
Supplier
Taiyo International — Suntheanine®
Suntheanine® is the only pure L-isomer L-theanine with its own body of clinical research. Every batch is GMP-certified, kosher, and halal.
Encapsulation
Singapore · cGMP facility
Blended, filled, sealed, and shipped from a single cGMP-certified facility here in Singapore. No contract-hopping, no mystery middle steps.
