NOW Foods L-Theanine 200mg vs Bulk Glycine Powder

Q: Which is better, NOW Foods L-Theanine 200mg or Bulk Glycine Powder?

NOW Foods L-Theanine 200mg scores 85.0/100 while Bulk Glycine Powder scores 77.0/100 in our analysis. NOW Foods L-Theanine 200mg is the higher-rated product overall.

Q: Is NOW Foods L-Theanine 200mg worth the price compared to Bulk Glycine Powder?

NOW Foods L-Theanine 200mg scores 88.0/100 for value, while Bulk Glycine Powder scores 86.0/100. Check our price comparison above for the latest UK prices.

Side-by-side comparison of scores, ingredients, prices and real customer feedback for NOW Foods L-Theanine 200mg and Bulk Glycine Powder.

Last verified: 07 Apr 2026 · Based on 104 reviews

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85.0

Quick Answer

NOW Foods L-Theanine 200mg scores 85.0/100 vs Bulk Glycine Powder at 77.0/100. NOW Foods L-Theanine 200mg wins on effectiveness, ingredient quality, value for money.

Which is better: NOW Foods L-Theanine 200mg or Bulk Glycine Powder?

NOW Foods L-Theanine wins overall, scoring 85 versus Bulk Glycine's 77, with stronger and more consistent user-reported effectiveness. Glycine's £4.99 price makes it worth trying for anyone specifically targeting sleep quality or building a supplement stack on a tight budget.

— AIScored Editorial Team

How Do the Scores Compare?

NOW Foods L-Theanine 200mg

Bulk Glycine Powder

	NOW Foods L-Theanine 200mg NOW Foods	Bulk Glycine Powder Bulk
Overall Score	85.0	77.0
Effectiveness	82.0/100 Best	72.0/100
Ingredient Quality	91.0/100 Best	87.0/100
Value for Money	88.0/100 Best	86.0/100
Side Effects	89.0/100 Best	74.0/100
Certifications	90.0/100 Best	68.0/100
Best Price	£21.90 Amazon UK →	£4.99 Amazon UK → Cheapest
Price per Serving	£0.18 120 servings	£0.03 166 servings Best value
Form	Capsules	Powder
Dose	200mg L-theanine	3000mg glycine per serving
Third-Party Tested	✓ Yes	✓ Yes
Reviews Analysed	77	27

NOW Foods L-Theanine 200mg

Pros

✓Promotes calm focus without drowsiness — the single most consistent user-reported benefit across dozens of reviews
✓Highly effective as a caffeine stack — users report it eliminates jitters, hand tremors, and anxiety while preserving energy
✓Excellent value: 120 capsules at 200mg per capsule lasts months even with daily use
✓Clean, minimal formula using patented Suntheanine (pure L-isomer) plus 100mg inositol for added calming synergy

Cons

✗Effects are subtle for some users — those expecting dramatic, immediate relaxation may be underwhelmed
✗Rare paradoxical response: at least one reviewer reported worsened insomnia, likely due to mild serotonergic/alertness activity
✗May interact with psychiatric medications (SSRIs, benzodiazepines, MAOIs) — users should consult a doctor
✗Mild blood pressure-lowering effect may be a concern for those already prone to hypotension

Best For

Coffee drinkers wanting to eliminate caffeine jitters while keeping focus Office workers and students managing daily stress and mental fatigue People with mild anxiety seeking a non-sedating, non-prescription option Vegans and those avoiding allergens (gluten, dairy, soy, nuts, shellfish-free) Nootropic beginners looking for a well-researched, low-risk entry point

Amazon UK £21.90

View full review →

Bulk Glycine Powder

Pros

✓Clinical 3g serving matches research-backed dose for sleep quality improvement
✓100% pure glycine — zero fillers, flavourings, or additives
✓Excellent cost-per-serving: 166 servings at a competitive UK price
✓GMP certified and third-party tested; made in the UK with strong brand transparency

Cons

✗Individual response varies significantly — some users report glycine as stimulating rather than sedating
✗At least one Reddit user reported anhedonia and worsened sleep at 3g daily; personal titration advised
✗No NSF or Informed Sport certification — relevant for competitive athletes
✗Prop 65 heavy-metal concerns raised by one user; COA should be requested for long-term high-dose use

Best For

People optimising sleep quality or struggling with insomnia DIY supplement stackers building a pre-sleep protocol Athletes and gym-goers seeking overnight recovery support Vegans wanting a clean, plant-friendly amino acid Budget-conscious buyers wanting maximum servings per pound spent

Amazon UK £4.99

View full review →

What does the data say about NOW Foods L-Theanine 200mg vs Bulk Glycine Powder?

These two products serve genuinely different purposes despite both sitting in the amino acids category. NOW Foods L-Theanine delivers 200mg of L-theanine per capsule — a well-researched dose for promoting calm without sedation, particularly when paired with caffeine. Bulk Glycine Powder takes a different approach entirely, offering 3g of pure glycine per serving in powder form, matching the clinical dose used in sleep studies. One is a daytime tool for focus and stress; the other is primarily a night-time supplement for sleep quality and recovery. The delivery methods reflect that split: capsules suit the grab-and-go nature of L-theanine use, while glycine powder dissolves easily in water before bed.

If you drink coffee and find yourself anxious, jittery, or struggling to concentrate under stress, the NOW Foods option at £21.90 scores 85/100 and is hard to argue with — 120 capsules at 200mg is excellent longevity. The glycine at £4.99 for 166 servings offers remarkable value for anyone specifically targeting sleep or overnight muscle recovery, scoring 77/100 overall.

Practically speaking, glycine tastes naturally sweet, which makes it easy to take in water. The L-theanine capsules are standard size and well-tolerated. Both products are third-party tested. Note that glycine occasionally has a stimulating effect in some individuals rather than a sedating one, so starting below 3g and adjusting makes sense.

NOW Foods L-Theanine 200mg Winner 85.0/100

NOW Foods L-Theanine 200mg using patented Suntheanine is consistently praised by verified iHerb purchasers for delivering a calm, focused mental state without sedation — with the caffeine-pairing use case repeatedly highlighted as a standout benefit.

Effectiveness

NOW Foods L-Thea..

82.0/100

Bulk Glycine Powder

72.0/100

Ingredient Quality

NOW Foods L-Thea..

91.0/100

Bulk Glycine Powder

87.0/100

Value for Money

NOW Foods L-Thea..

88.0/100

Bulk Glycine Powder

86.0/100

Side Effects

NOW Foods L-Thea..

89.0/100

Bulk Glycine Powder

74.0/100

Certifications

NOW Foods L-Thea..

90.0/100

Bulk Glycine Powder

68.0/100

What are the key differences?

NOW Foods L-Theanine 200mg is best for: Coffee drinkers wanting to eliminate caffeine jitters while keeping focus, Office workers and students managing daily stress and mental fatigue

Bulk Glycine Powder is best for: People optimising sleep quality or struggling with insomnia, DIY supplement stackers building a pre-sleep protocol

Frequently Asked Questions

Which is better, NOW Foods L-Theanine 200mg or Bulk Glycine Powder? ▼

NOW Foods L-Theanine 200mg scores 85.0/100 overall while Bulk Glycine Powder scores 77.0/100. NOW Foods L-Theanine 200mg comes out ahead, scoring higher on effectiveness (82.0 vs 72.0). NOW Foods L-Theanine 200mg is best suited for Coffee drinkers wanting to eliminate caffeine jitters while keeping focus and Office workers and students managing daily stress and mental fatigue. Bulk Glycine Powder is better for People optimising sleep quality or struggling with insomnia and DIY supplement stackers building a pre-sleep protocol.

Is NOW Foods L-Theanine 200mg worth the price compared to Bulk Glycine Powder? ▼

NOW Foods L-Theanine 200mg costs £21.90 while Bulk Glycine Powder is £4.99. For value, NOW Foods L-Theanine 200mg scores 88.0/100 vs Bulk Glycine Powder's 86.0/100. NOW Foods L-Theanine 200mg delivers better value relative to its quality. Note that NOW Foods L-Theanine comes as capsules while Bulk Glycine Powder is powder, which may affect your preference.

Which has fewer side effects? ▼

NOW Foods L-Theanine 200mg scores 89.0/100 for side effects (higher means fewer reported issues) while Bulk Glycine Powder scores 74.0/100. Reviewers report fewer side effects with NOW Foods L-Theanine 200mg. For certification and testing, NOW Foods L-Theanine scores 90.0/100 vs Bulk Glycine Powder's 68.0/100. Always consult a healthcare professional before starting any supplement.

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Disclaimer: AIScored provides data-driven comparisons based on publicly available reviews. This is not medical advice. Affiliate links may earn us a commission at no extra cost to you.

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