Ingredient
Amino acids and GABA in ZenCortex: What the Label and the Research Say
Amino acids and GABA make up eight of the 22 lines in ZenCortex: L-glutamine, L-tyrosine, L-arginine, beta-alanine, GABA, L-ornithine, L-tryptophan and L-carnitine. By label order each can weigh at most 9.1 to 14.3 mg per 1 mL serving. Studies of these compounds use far larger doses, and none looked at hearing.
Written by the ZenCortex label deskUpdated
The basics01
Which amino acids and GABA are in ZenCortex?
ZenCortex lists eight amino acid lines: L-glutamine, L-tyrosine, L-arginine, beta-alanine, GABA, L-ornithine HCl, L-tryptophan and L-carnitine. They sit in places 14 to 17 and 19 to 22.
Amino acids are protein building blocks, and GABA is also a calming brain messenger.
Label math02
How much of each amino acid is in ZenCortex?
The label prints no amount for any of them. By label order, each can weigh at most 9.1 to 14.3 mg per serving.
The calculation is 200 mg divided by the line's place: 200 divided by 14 gives 14.3 mg for L-glutamine, and 200 divided by 22 gives 9.1 mg for L-carnitine. Two droppers a day double it. These are limits from the listing-order rule (eCFR, 21 CFR 101.36 Supplement Facts), not lab results.
Research03
What does research say about these amino acids?
The research is about other jobs, at far higher doses, and not about hearing.
Beta-alanine
Tingling starts at 800 mg at once (NIH ODS, Exercise and Athletic Performance), about 68 times the 11.8 mg ceiling.
L-carnitine
About 3 g a day causes nausea and fishy odor (NIH ODS, Carnitine), 330 times the 9.1 mg ceiling.
L-glutamine and L-arginine
Evidence is lacking for muscle gain with glutamine (MSK, Glutamine), and arginine's heart evidence is mixed (MSK, Arginine).
L-tryptophan
It is linked with serotonin syndrome when combined with serotonin-affecting medicines (Cleveland Clinic, Serotonin Syndrome).
For L-tyrosine, GABA and L-ornithine we found no authoritative page, so we make no evidence claim (NCCIH, Using Dietary Supplements Wisely).
At a glance04
What are the amino acid and GABA facts in tables?
Eight tables follow, one per label line.
| Name on the label | L-Glutamine |
|---|---|
| What it is | An amino acid the body makes and gets from food |
| Place on the label | Line 14 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 14.3 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | No standard dose on the cited page |
| Strength of evidence | The page states evidence is lacking for muscle gain; surgery and cancer-care findings are mixed. Nothing on hearing |
| Marketed or traditional use | Marketed for recovery and gut health |
| Main caution | Case reports include liver and kidney harm at high doses; do not confuse it with glutamate. |
| Name on the label | L-Tyrosine |
|---|---|
| What it is | An amino acid used to make dopamine and thyroid hormone |
| Place on the label | Line 15 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 13.3 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | No cited page found for a dose |
| Strength of evidence | We could not fetch an authoritative page for L-tyrosine, so we make no evidence claim about it |
| Marketed or traditional use | Marketed for focus |
| Main caution | Ask a pharmacist about thyroid medicine and MAO-inhibitor antidepressants before using any amino acid supplement. |
| Name on the label | L-Arginine |
|---|---|
| What it is | An amino acid that helps make nitric oxide |
| Place on the label | Line 16 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 12.5 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | No standard dose on the cited page |
| Strength of evidence | Heart evidence is mixed; long-term use worsened peripheral artery disease in one trial. Nothing on hearing |
| Marketed or traditional use | Marketed for circulation |
| Main caution | Belly pain, bloating, nausea and diarrhea are reported; it may add to blood-pressure drugs. |
| Name on the label | Beta-Alanine |
|---|---|
| What it is | An amino acid used by athletes |
| Place on the label | Line 17 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 11.8 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | 800 mg or more at once can cause tingling lasting about an hour |
| Strength of evidence | Possible small benefit in high-intensity efforts of 30 seconds to 10 minutes; safety data cover 1.6 to 6.4 g a day for up to 8 weeks. Nothing on hearing |
| Marketed or traditional use | Marketed for exercise performance |
| Main caution | Tingling in the face, neck and hands is harmless but can be unpleasant. |
| Name on the label | GABA (Gamma aminobutyric acid) |
|---|---|
| What it is | The brain's main calming chemical messenger, also sold as a supplement |
| Place on the label | Line 19 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 10.5 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | No cited page found for a dose |
| Strength of evidence | We could not fetch an authoritative page for GABA, so we make no evidence claim about it |
| Marketed or traditional use | Marketed for calm and sleep |
| Main caution | A calming-marketed compound; it may add to sedatives. Ask a pharmacist. |
| Name on the label | L-Ornithine HCl |
|---|---|
| What it is | An amino acid in the urea cycle |
| Place on the label | Line 20 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 10 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | No cited page found for a dose |
| Strength of evidence | We could not fetch an authoritative page for L-ornithine, so we make no evidence claim about it |
| Marketed or traditional use | Marketed for recovery and sleep |
| Main caution | Amino acids in large doses can upset the stomach; ask a pharmacist. |
| Name on the label | L-Tryptophan |
|---|---|
| What it is | An amino acid the body uses to make serotonin and melatonin |
| Place on the label | Line 21 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 9.5 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | No standard dose on the cited page |
| Strength of evidence | A secondary source links tryptophan with serotonin syndrome when combined with serotonin-affecting medicines. Nothing on hearing |
| Marketed or traditional use | Marketed for calm and sleep |
| Main caution | Serotonin syndrome is a medical emergency; do not combine with antidepressants or similar medicines without a doctor. |
| Name on the label | L-Carnitine |
|---|---|
| What it is | An amino acid derivative that moves fat into cells for energy |
| Place on the label | Line 22 of 22 in the 200 mg proprietary blend |
| Amount per serving (1 mL) | At most 9.1 mg per 1 mL serving (label order); 9.1 mg if the 22 lines were split evenly |
| What research used | About 3 g a day can cause nausea, vomiting, cramps, diarrhea and fishy body odor; no upper limit is set |
| Strength of evidence | Evidence is mixed: a Cochrane review found routine use for dementia not justified. Nothing on hearing |
| Marketed or traditional use | Marketed for energy |
| Main caution | Can cause seizures in people with seizure disorders; some anticonvulsants lower blood carnitine. |
ZenCortex: from $49 a bottle60 mL drops · 2, 3 or 6 bottles · free US shipping on 3 and 6 · 60-day guarantee
See packsCautions05
Are amino acids and GABA safe with medicines?
At these tiny ceilings the risks are small, but a few are worth knowing. Tryptophan can matter with antidepressants (Cleveland Clinic, Serotonin Syndrome).
Arginine may add to blood-pressure drugs (MSK, Arginine). Carnitine can cause seizures in people with seizure disorders (NIH ODS, Carnitine). For tyrosine, GABA and ornithine, ask a pharmacist (NCCIH, Using Dietary Supplements Wisely).
Never stop or change a dose because you started a supplement.
Claims vs evidence06
Do amino acids and GABA help hearing?
No study we found shows that these amino acids or GABA help hearing. The bottle claims only "Supports Healthy Hearing†" for the whole product.
The NIDCD says no supplement has been proven effective for tinnitus (NIDCD, Tinnitus). A hearing test is the first step if hearing changes (NIDCD, Who Can I Turn to for Help with Hearing Loss).
Keep reading07
Should amino acids affect your decision to buy ZenCortex?
They matter most with antidepressants, blood-pressure drugs or anticonvulsants. Packs run $79, $69 or $49 a bottle (ZenCortex info page).
FAQ08
ZenCortex questions people ask
Which amino acids are in ZenCortex?
ZenCortex lists L-glutamine, L-tyrosine, L-arginine, beta-alanine, L-ornithine HCl, L-tryptophan and L-carnitine, plus GABA. None has a printed amount.
How many milligrams of GABA are in ZenCortex?
The label does not say. Listed 19th in a 200 mg blend, GABA can weigh at most 10.5 mg per dropper, which is 200 divided by 19.
Does the beta-alanine in ZenCortex cause tingling?
Unlikely. Tingling starts at 800 mg or more at once (NIH ODS, Exercise and Athletic Performance), and beta-alanine here can weigh at most 11.8 mg per dropper, about 68 times lower.
Is the L-carnitine in ZenCortex enough to matter?
Probably not. About 3 g a day can cause nausea and fishy odor (NIH ODS, Carnitine), and L-carnitine here can weigh at most 9.1 mg per serving.
Can L-tryptophan in ZenCortex interact with antidepressants?
It may. Tryptophan is linked with serotonin syndrome when combined with serotonin-affecting medicines (Cleveland Clinic, Serotonin Syndrome). Ask your doctor first.
Are the amino acids in ZenCortex a protein supplement?
No. The most any one line can weigh is 14.3 mg per dropper, far below the grams in a protein supplement.
Who wrote this09
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by Thezencortex, a retailer of ZenCortex, not by the manufacturer. We earn money when you buy through our order links.
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