Comparison
L-Theanine vs Sermorelin
Side-by-side of L-Theanine and Sermorelin. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
L-Theanine
L-theanine is a non-protein amino acid found in tea leaves. The most-replicated nootropic; pairs with caffeine at 1:1 (100-200 mg each) for acute focus.
Sermorelin
Sermorelin peptide therapy uses a 29-amino-acid GHRH analog to raise endogenous GH. Dosing, half-life, sermorelin vs ipamorelin, and safety.
Effects at a glance
L-Theanine
- •Non-protein amino acid in tea; the most-replicated nootropic in the human RCT literature
- •Caffeine + theanine at 1:1 (100-200 mg each) is the gold-standard acute focus stack
- •Solo doses of 200-400 mg reduce subjective stress and improve sleep quality
- •Increases alpha-wave EEG activity within 30-45 minutes of 200 mg oral dose
- •Crosses blood-brain barrier; bioavailability high, half-life 60-90 minutes
- •Clean safety record; minimal interactions at supplement doses
Sermorelin
- •Synthetic 29-amino-acid GHRH fragment; FDA approved 1997 for pediatric GH deficiency as Geref
- •Voluntarily discontinued by Serono in 2008 for commercial reasons; not safety-related
- •Compounded by 503A/503B pharmacies for off-label adult anti-aging and body-composition use
- •Produces physiologic pulsatile GH release; ~10 to 20 minute plasma half-life
- •Standard anti-aging clinic protocol: 200 to 500 mcg subcutaneously pre-bed, often with ipamorelin
- •Banned by WADA under S2 (peptide hormones, growth factors)
Side-by-side
| Attribute | L-Theanine | Sermorelin |
|---|---|---|
| Category | supplement | peptide |
| Also known as | theanine, gamma-glutamylethylamide | Sermorelin acetate, GRF 1-29, Geref, GHRH (1-29) NH2 |
| Half-life (hr) ↗ | 1.5 | 0.25 |
| Typical dose (mg) ↗ | 200 | 0.3 |
| Dosing frequency | as needed (with caffeine) or daily | 1-2x daily |
| Routes | oral | subcutaneous |
| Onset (hr) | 0.5 | 0.25 |
| Peak (hr) | 1 | 0.5 |
| Molecular weight | 174.2 | 3357.88 |
| Molecular formula | C7H14N2O3 | C149H246N44O42S |
| Mechanism | Crosses BBB; modulates GABA/dopamine/serotonin (modest); increases alpha-wave EEG activity; dampens stress-induced sympathetic response without sedation. | Synthetic 29-amino-acid GHRH fragment that binds the GHRH receptor on pituitary somatotrophs to stimulate endogenous pulsatile GH synthesis and release while preserving the GH-IGF-1 negative feedback loop. |
| Legal status | OTC dietary supplement | FDA approved 1997 (Geref, pediatric GHD); voluntarily discontinued by Serono 2008; compounded by 503A/503B pharmacies for off-label adult use; banned by WADA |
| WADA status | allowed | banned |
| DEA / Rx | OTC supplement | Rx only via compounding (no controlled-substance schedule) |
| Pregnancy | Insufficient supplement-dose data; tea-source intake safe | Category C (historical labeling); not recommended in pregnancy |
| CAS | 3081-61-6 | 86168-78-7 |
| PubChem CID | 439378 | 16129617 |
| Wikidata | Q909931 | Q416620 |
Safety profile
L-Theanine
Common side effects
- mild GI upset (rare)
- headache (rare)
Contraindications
- pregnancy / lactation (insufficient data at supplement doses)
- concurrent strong GABAergics without caution
Interactions
- caffeine: synergistic for acute focus; dampens jitter without blunting alertness(minor)
- benzodiazepines / alcohol: potential additive sedation(minor)
Sermorelin
Common side effects
- injection-site pain or irritation
- transient flushing
- headache
- vivid dreams (pre-bed dosing)
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- diabetic retinopathy (theoretical)
- untreated hypothyroidism
Interactions
- ipamorelin: synergistic GH release via parallel GHRH and ghrelin pathways; standard anti-aging clinic pairing(minor)
- CJC-1295: pharmacologically redundant (both GHRH-pathway); typically not stacked(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: blunt GH response; reduce expected efficacy(moderate)
- levothyroxine (untreated hypothyroidism): untreated hypothyroidism blunts GH response; correct thyroid first(moderate)
Which Should You Take?
L-Theanine comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. Sermorelin is the right call when one of the conditionals below applies.
- → If your priority is focus or working memory, pick L-Theanine.
- → If your priority is stress and HPA-axis regulation, pick L-Theanine.
- → If your priority is growth-hormone axis, pick Sermorelin.
- → If your priority is healthspan extension, pick Sermorelin.
Edge case: If you want to avoid FDA approved 1997 (Geref, pediatric GHD); voluntarily discontinued by Serono 2008; compounded by 503A/503B pharmacies for off-label adult use; banned by WADA, L-Theanine is the more accessible choice.
Default choice: L-Theanine. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Sermorelin only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between L-Theanine and Sermorelin?
L-Theanine and Sermorelin differ in category (supplement vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, L-Theanine or Sermorelin?
L-Theanine half-life is 1.5 hours; Sermorelin half-life is 0.25 hours.
Can you stack L-Theanine with Sermorelin?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper