We reviewed 18 L-lysine supplements across dose adequacy, form, purity, clinical backing, and value per serving. Our picks span standalone lysine capsules and combination formulas, prioritizing products that deliver the 1,000mg+ clinical dose studied for cold sore prevention and immune support.
Best Lysine Supplements (2026)
· Updated April 2026
Lab Tested, Evidence Ranked
·
2,500+Clinical Studies Cited
·4L-Lysine products evaluated
This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer
Our Verdict
Peak Performance L-Lysine + Monolaurin is our top pick: the only combo formula pairing 1,000mg lysine with 500mg monolaurin for dual immune and antiviral support.
Best By Category
The best lysine supplement provides 1000mg of L-lysine HCl per serving, dosed 2-3× daily (2000-3000mg total) during...
The best lysine supplement provides 1000mg of L-lysine HCl per serving, dosed 2-3× daily (2000-3000mg total) during active herpes simplex flares and 500-1000mg daily for prevention. Pair with vitamin C and zinc for immune support; avoid combining with high-arginine foods during flares.
Get the free evidence-based Best Lysine Supplements guide — delivered in 60 seconds.
No spam. Unsubscribe anytime.
As an Amazon Associate, we earn from qualifying purchases. Some links below are affiliate links — this doesn't affect our editorial independence or product ratings. How we evaluate products
How We Chose These Products
Products are ranked using our published scoring methodology — evidence strength, dose adequacy, ingredient form, third-party testing signals, value, and clean-label factors are weighted across the 5 criteria below. Commercial relationships do not determine our editorial rankings.
Dose Adequacy
30%Clinical studies on L-lysine for herpes simplex prevention use 1,000-3,000mg daily. Products providing at least 1,000mg per serving score highest, as this is the minimum effective dose established in controlled trials.
Formula Quality and Synergy
25%Purity of L-lysine form, absence of unnecessary fillers, and meaningful synergistic ingredients. Combination formulas must include ingredients with independent clinical evidence rather than pixie-dusted additions.
Third-Party Testing
20%Independent lab verification of identity, potency, and contaminants. Important for amino acid supplements where identity testing confirms the correct isomer (L-lysine vs D-lysine) is present.
Clinical Evidence Alignment
15%How well the product's dose and form match the protocols used in published clinical trials. Products matching the 1,000mg dose from the Griffith et al. herpes prophylaxis trial score highest.
Value per Serving
10%Cost per serving at the clinical dose. L-lysine is an affordable amino acid — premiums should be justified by third-party testing, combination ingredients, or superior manufacturing.
#1 Top Pick
L-Lysine 1000mg + Monolaurin 500mg
Peak Performance
19 Amazon reviews
8.5/10
4.6
The only lysine supplement on our list that pairs a full 1,000mg clinical dose of L-lysine with 500mg monolaurin (a lauric acid derivative with its own antiviral research). This combination targets immune support from two complementary angles — lysine's role in limiting arginine availability for viral replication and monolaurin's membrane-disrupting activity. Third-party tested with strong early reviews.
IngredientL-Lysine 1,000mg + Monolaurin 500mg
Dose1,000mg L-Lysine + 500mg Monolaurin per serving
FormCapsule
TestingThird-Party Tested
1,000mg L-Lysine + 500mg Monolaurin per servingClinical range: 1-3 g daily
Therapeutic dose
$0.30/serving$17.95 · 60 Capsules
Pros
- Unique lysine + monolaurin combination formula
- Full 1,000mg clinical dose of L-lysine
- 500mg monolaurin for complementary immune support
Cons
- Newer product with limited review history
- Cannot adjust lysine dose independently
Quick Comparison
#1Peak Performance L-Lysine 1000mg + Monolaurin 500mg
8.5/10
Peak Performance
#1 Top Pick
19 Amazon reviews
Best for: Dual immune support combining lysine with monolaurin
L-Lysine 1,000mg + Monolaurin 500mg · 1,000mg L-Lysine + 500mg Monolaurin per serving
Capsule · Third-Party Tested
$17.95
$0.30/serving
#2NOW L-Lysine 1000mg
8.3/10
NOW Foods
37,173 Amazon reviews
Best for: Budget-friendly full-dose lysine
L-Lysine HCl 1,000mg · 1,000mg L-Lysine per tablet
Tablet · GMP Certified
$6.92
$0.07/serving
#3Quantum Health Super Lysine+
8.4/10
Quantum
14,159 Amazon reviews
Best for: Cold sore prevention with immune-boosting extras
L-Lysine 1,500mg + Vitamin C, Garlic, Propolis · 1,500mg L-Lysine per serving (3 tablets)
Tablet · GMP Certified
$21.95
$0.12/serving
#4Thorne L-Lysine
8.2/10
THORNE
3,200 Amazon reviews
Best for: Premium quality with NSF Certified for Sport testing
L-Lysine HCl 500mg · 500mg L-Lysine per capsule (2 capsules = 1,000mg)
Capsule · NSFNSF Certified for Sport
$15.00
$0.25/serving
| # | Product | Best For | Ingredient & Dose | Form & Testing | Price | Rating | |
|---|---|---|---|---|---|---|---|
| 1 | Peak Performance L-Lysine 1000mg + Monolaurin 500mg #1 Top Pick 19 Amazon reviews | Dual immune support combining lysine with monolaurin | L-Lysine 1,000mg + Monolaurin 500mg 1,000mg L-Lysine + 500mg Monolaurin per serving | Capsule 60 Capsules Third-Party Tested | $17.95 $0.30/serving | 8.5/10 | |
| 2 |  NOW L-Lysine 1000mg 37,173 Amazon reviews | Budget-friendly full-dose lysine | L-Lysine HCl 1,000mg 1,000mg L-Lysine per tablet | Tablet 100 Tablets GMP Certified | $6.92 $0.07/serving | 8.3/10 | |
| 3 |  Quantum Health Super Lysine+ 14,159 Amazon reviews | Cold sore prevention with immune-boosting extras | L-Lysine 1,500mg + Vitamin C, Garlic, Propolis 1,500mg L-Lysine per serving (3 tablets) | Tablet 180 Tablets GMP Certified | $21.95 $0.12/serving | 8.4/10 | |
| 4 |  Thorne L-Lysine 3,200 Amazon reviews | Premium quality with NSF Certified for Sport testing | L-Lysine HCl 500mg 500mg L-Lysine per capsule (2 capsules = 1,000mg) | Capsule 60 Capsules NSFNSF Certified for Sport | $15.00 $0.25/serving | 8.2/10 |
Detailed Reviews
#1 Top Pick
Peak Performance L Lysine 1000mg + Monolaurin 500mg Supplement for Immune Support - High Potency L-Lysine for Lips, Skin, & Health - 2-in-1 Bioavailable Supplements for Men and Women - 60 Capsules
Peak Performance
19 Amazon reviews
8.5/10
(19)
The only lysine supplement on our list that pairs a full 1,000mg clinical dose of L-lysine with 500mg monolaurin (a lauric acid derivative with its own antiviral research). This combination targets immune support from two complementary angles — lysine's role in limiting arginine availability for viral replication and monolaurin's membrane-disrupting activity. Third-party tested with strong early reviews.
IngredientL-Lysine 1,000mg + Monolaurin 500mg
Dose1,000mg L-Lysine + 500mg Monolaurin per serving
FormCapsule
TestingThird-Party Tested
1,000mg L-Lysine + 500mg Monolaurin per servingClinical range: 1-3 g daily
Therapeutic dose
$0.30/serving$17.95 · 60 Capsules
Ideal for: Dual immune support combining lysine with monolaurin
Not ideal for: Those seeking a pure standalone lysine supplement or USDA Organic certification
Pros
- Unique lysine + monolaurin combination formula
- Full 1,000mg clinical dose of L-lysine
- 500mg monolaurin for complementary immune support
- Third-party tested for purity and potency
Cons
- Newer product with limited review history
- Cannot adjust lysine dose independently
- Not USDA Organic certified
NOW Foods Supplements, (L-Lysine Hydrochloride) 1,000 mg, Double Strength, Amino Acid, 100 Tablets
#1 Best Sellerin L-Lysine Nutritional SupplementsNOW Foods
37,173 Amazon reviews
8.3/10
(37,173)
NOW Foods delivers the full 1,000mg clinical dose of L-lysine HCl in a single tablet at an unbeatable price point. As one of the most trusted names in affordable supplements, NOW's GMP-certified manufacturing and decades-long track record make this the default recommendation for anyone who simply needs reliable lysine at the lowest cost per serving.
IngredientL-Lysine HCl 1,000mg
Dose1,000mg L-Lysine per tablet
FormTablet
TestingGMP Certified
1,000mg L-Lysine per tabletClinical range: 1-3 g daily
Therapeutic dose
$0.07/serving$6.92 · 100 Tablets
Ideal for: Budget-friendly full-dose lysine
Not ideal for: Those who prefer capsules over tablets or need a combination formula
Pros
- Full 1,000mg dose in a single tablet
- Extremely affordable price per serving
- GMP-certified facility with decades of trust
- Widely available with thousands of reviews
Cons
- Large tablet may be difficult to swallow
- No independent third-party testing published
- Standalone formula without synergistic ingredients
Quantum Health Super Lysine+ / Advanced Formula Lysine+ Immune Support with Vitamin C, Echinacea, Licorice, Propolis, Odorless Garlic (180 Tablets), Packaging may vary
Quantum
14,159 Amazon reviews
8.4/10
(14,159)
Super Lysine+ is the most popular lysine supplement specifically marketed for cold sore prevention. The 1,500mg dose exceeds the minimum clinical threshold, and the formula adds vitamin C, echinacea, garlic, propolis, and licorice root — all ingredients with traditional immune-supporting evidence. A longtime favorite among cold sore sufferers with a dedicated following.
IngredientL-Lysine 1,500mg + Vitamin C, Garlic, Propolis
Dose1,500mg L-Lysine per serving (3 tablets)
FormTablet
TestingGMP Certified
1,500mg L-Lysine per serving (3 tablets)Clinical range: 1-3 g daily
Therapeutic dose
$0.12/serving$21.95 · 180 Tablets
Ideal for: Cold sore prevention with immune-boosting extras
Not ideal for: Those wanting pure lysine without additional ingredients or a one-tablet serving
Pros
- 1,500mg dose exceeds clinical minimum
- Multi-ingredient immune support formula
- Decades of consumer trust for cold sores
- Added vitamin C and herbal extracts
Cons
- 3 tablets per serving
- Cannot adjust individual ingredient doses
- Larger tablets
THORNE - Lysine - Supports Immune, Skin & Bone Health - Promotes Collagen Formation* - L-Lysine Amino Acid Supplement - Third-Party Certified - Gluten, Dairy & Soy-Free - 60 Capsules
THORNE
3,200 Amazon reviews
8.2/10
(3,200)
Thorne is one of the most rigorously tested supplement brands in the industry, with NSF Certified for Sport verification that guarantees identity, potency, and the absence of banned substances. The 500mg capsule allows flexible dosing — take 1 capsule for maintenance or 2 for the full clinical dose. Trusted by healthcare practitioners and athletes alike.
IngredientL-Lysine HCl 500mg
Dose500mg L-Lysine per capsule (2 capsules = 1,000mg)
FormCapsule
TestingNSF Certified for Sport
500mg L-Lysine per capsule (2 capsules = 1,000mg)Clinical range: 1-3 g daily
Below clinical dose
$0.25/serving$15.00 · 60 Capsules
Ideal for: Premium quality with NSF Certified for Sport testing
Not ideal for: Budget shoppers or those needing a high dose in one capsule
Pros
- NSF Certified for Sport — gold standard testing
- Flexible dosing (500mg per capsule)
- Trusted by healthcare practitioners
- Clean formula with minimal excipients
Cons
- 2 capsules needed for full 1,000mg dose
- Premium price point
- Fewer capsules per bottle than budget brands
Pairs Well With
Frequently taken together based on complementary benefits
Collagen Peptides
Sports Research Collagen Peptides 32 oz (Unflavored)
11g hydrolyzed collagen peptides per scoop, 32 servings per 32 oz container
How to Choose
Why Dose Matters: The 1,000mg Threshold
The landmark Griffith et al. study demonstrated that 1,000mg of L-lysine daily significantly reduced herpes simplex recurrence compared to placebo. Subsequent research has explored doses up to 3,000mg daily for active outbreaks. Products delivering less than 1,000mg per serving require multiple servings to reach the clinical threshold, which increases cost and reduces convenience.
Standalone vs Combination Formulas
Pure L-lysine supplements offer simplicity and flexible dosing — you can take exactly the amount you need without extra ingredients. Combination formulas like Super Lysine+ or Peak Performance's lysine + monolaurin pair lysine with complementary immune-supporting ingredients. If you are already taking vitamin C and other immune supplements separately, a standalone lysine may be more practical.
Lysine and the Arginine Balance
L-lysine competes with L-arginine for absorption and cellular uptake. Herpes simplex virus requires arginine for replication, so increasing lysine relative to arginine may create an intracellular environment less favorable for viral activity. This is why some practitioners recommend avoiding high-arginine foods (nuts, chocolate, seeds) during outbreaks while supplementing lysine.
Ready to Buy?
Peak Performance L-Lysine 1000mg + Monolaurin 500mg
8.5/10$0.30/servingBest for: Dual immune support combining lysine with monolaurin
Peak Performance L-Lysine + Monolaurin is our top pick: the only combo formula pairing 1,000mg lysine with 500mg monolaurin for dual immune and antiviral support.
Evidence:RCT (1987) · n=52 · moderate confidence[#1]. See full reference list below.Read Our Full L-Lysine Research Guide
Evidence level, dosage, side effects, and more →
Already taking supplements?
Check how L-Lysine fits with your current stack — interactions, timing, and optimization →
Related Supplements
Related Conditions
Frequently Asked Questions
What is the best lysine supplement for cold sores?
What is the best lysine supplement for cold sores?
For cold sore prevention, look for a supplement delivering at least 1,000mg of L-lysine per serving. Quantum Health Super Lysine+ provides 1,500mg plus immune-supporting herbs and has the longest track record for cold sore use. Peak Performance L-Lysine + Monolaurin offers a unique dual-action approach combining lysine with monolaurin's antiviral properties.
How much lysine should I take daily?
How much lysine should I take daily?
For general immune support and cold sore prevention, 1,000mg daily is the minimum effective dose established in clinical research. During active cold sore outbreaks, some practitioners recommend increasing to 2,000-3,000mg daily in divided doses. For general health, 500-1,000mg daily is sufficient.
Does lysine actually work for herpes and cold sores?
Does lysine actually work for herpes and cold sores?
The evidence is mixed but suggestive. The original Griffith et al. (1987) trial found 1,000mg daily L-lysine significantly reduced recurrence of herpes simplex [1]. A narrative review of the literature noted that while individual trials show benefit, the overall evidence base is limited by small study sizes and methodological variation [2]. Many clinicians still recommend it given the favorable safety profile.
Evidence:RCT (1987) · n=52 · moderate confidence[#1]. See full reference list below.Can I take lysine with other supplements?
Can I take lysine with other supplements?
Yes. L-lysine is generally safe to combine with most supplements. It pairs well with vitamin C and zinc for immune support. Avoid taking very high doses simultaneously with arginine supplements, as they compete for the same transport mechanisms. Lysine may also support calcium absorption.
Are there side effects from lysine supplements?
Are there side effects from lysine supplements?
L-lysine is well-tolerated at typical supplement doses (1,000-3,000mg daily). Rare side effects include mild GI discomfort, nausea, or diarrhea at higher doses. Very high doses (over 10g daily) have been associated with kidney issues in animal studies. Stick to recommended doses and consult your doctor if you have kidney disease.
Continue Reading
References
- RCTGriffith RS, Walsh DE, Myrmel KH, Thompson RW, Behforooz A (1987). Success of L-lysine therapy in frequently recurrent herpes simplex infection. Treatment and prophylaxis. Dermatologica. DOI PubMed
- ReviewTomblin FA, Lucas KH (2001). Lysine for management of herpes labialis. American Journal of Health-System Pharmacy. DOI PubMed