Finding Selank online is not particularly difficult. Determining whether a supplier provides adequately tested and accurately labeled research materials is a much bigger challenge.
We compared three Selank suppliers based on the factors that matter most when evaluating a research peptide vendor:
- Independent laboratory testing
- Published Certificates of Analysis
- Reported purity
- Price and vial size
- Shipping policies
- Return or replacement protection
- Overall company transparency
Based on these criteria, BioInfinity is our top overall selection, followed by Limitless Biotech and Sports Technology Labs.
Important Research Notice: The products discussed below are sold strictly for laboratory research and are not intended for human or animal consumption. Selank is not an FDA-approved medication. The FDA states that it lacks important safety information regarding Selank acetate administered to humans and has identified potential immunogenicity concerns associated with certain routes of administration.
Prices and product information were checked on July 2, 2026 and may change.
Best Selank Vendors at a Glance
| Company | Vial Size | Listed Price | Best For |
|---|---|---|---|
| #1. BioInfinity | 10 mg | $70 | Best overall |
| #2. Limitless Biotech | 20 mg or 30 mg | $40.99–$51.99 | Best value and larger quantities |
| #3. Sports Technology Labs | 5 mg | $54.99 | Best testing transparency |
#1. BioInfinity — Best Overall Place to Buy Selank
Click Here Now to see the official Selank page on the Bioinfinity website.
BioInfinity takes our top position because it currently offers the best overall combination of verified purity, batch-specific testing, reasonable vial size and fast domestic shipping.
Its Selank is sold in a 10 mg lyophilized vial for $70, making the standard price approximately $7 per milligram. The company also offers automatic quantity discounts:
- Three to five vials: $59.50 each
- Six or more vials: $56 each
The most compelling part of the listing is the available batch information. BioInfinity identifies the current batch number, testing date, laboratory and analytical methods directly on the product page.
The displayed Certificate of Analysis reports 99.97% purity for the current batch. Testing was performed by Verum Analytics using HPLC-UV/MS, which helps evaluate both purity and chemical identity.
BioInfinity also ships orders placed before 2:00 p.m. Eastern Time on the same business day. Standard UPS Ground shipping is listed at $7.99, while orders of at least $200 qualify for free UPS two-day shipping. The company currently ships throughout the United States but does not offer international delivery.
Why BioInfinity Ranked First
BioInfinity does not offer the lowest initial price in this comparison. However, it provides a better balance of vial size, current batch testing, reported purity and shipping speed than the other suppliers evaluated.
The 10 mg vial is also a useful middle ground. It contains twice as much material as the Sports Technology Labs product without requiring the purchase of the much larger 20 mg or 30 mg quantities offered by Limitless Biotech.
BioInfinity Pros
- Current batch reports 99.97% purity
- Testing laboratory and methods are clearly identified
- Batch-specific COA available from the product page
- Same-day shipping on qualifying weekday orders
- Discounts begin at three vials
- U.S.-based fulfillment and customer support
BioInfinity Cons
- More expensive per milligram than Limitless Biotech
- Free shipping requires a $200 order
- No international shipping
- Eligible returns are limited to unopened products within 14 days and may incur a 15% restocking fee
Our Verdict: BioInfinity is our top overall selection for researchers who prioritize a strong current purity result, visible batch information and a straightforward 10 mg vial.
#2. Limitless Biotech — Best Value and Largest Vial Sizes
Click Here Now to see the official Selank page on the Limitless Biotech website.
Limitless Biotech stands out for the amount of research material offered for the price.
Its product is available in 20 mg and 30 mg quantities, with listed prices ranging from $40.99 to $51.99. That is substantially more material for the money than either of the conventional Selank products in this comparison.
Limitless also offers volume discounts of 5% when purchasing five to nine units, 10% for 10 to 14 units and 15% for orders of at least 15 units.
There is, however, an important distinction: Limitless sells N-Acetyl Selank rather than standard Selank.
N-Acetyl Selank is a chemically modified form and should not automatically be treated as identical to ordinary Selank. Researchers should confirm that the acetylated form is appropriate for the particular experiment, reference standard or protocol being followed.
Limitless says its product is manufactured in the United States and tested by independent laboratories. Its product page provides separate downloadable reports for:
- Purity
- Sterility
- Endotoxins
Reports are listed for both the 20 mg and 30 mg batches. The product specifications state a purity of at least 99% by HPLC, although the headline quality statement elsewhere on the page refers to a minimum standard of at least 98.5%.
This broader testing package is a meaningful advantage. A purity percentage alone does not establish sterility or determine whether endotoxins are present, so having separate reports provides additional information for researchers who require those parameters.
Limitless advertises same-day shipping and can ship to many international destinations, although customers are responsible for determining whether the product can legally clear customs in their country. Return requests must generally be submitted within 10 days of delivery.
Limitless Biotech Pros
- Largest quantities in this comparison
- Lowest listed cost relative to vial size
- Published purity, sterility and endotoxin reports
- 20 mg and 30 mg options
- Same-day shipping advertised
- International shipping available to many locations
- Volume discounts of up to 15%
Limitless Biotech Cons
- Product is N-Acetyl Selank, not conventional Selank
- Shorter 10-day return-request window
- International deliveries are not protected against customs seizures or refusals
- Product page uses both ≥98.5% and ≥99% purity language
Our Verdict: Limitless Biotech is the most attractive option for research requiring larger amounts of N-Acetyl Selank. Its value is difficult to beat, but buyers should understand that this is a modified version rather than the same Selank product offered by BioInfinity and Sports Technology Labs.
#3. Sports Technology Labs — Best Testing Transparency
Click Here Now to see the official Selank page on the Sports Technology Labs website.
Sports Technology Labs ranks third overall, but it deserves recognition for presenting its testing information in an unusually clear and accessible format.
The company sells a 5 mg vial of Selank for $54.99. Its current Certificate of Analysis reports 96.84% purity, with identity and purity testing performed by MZ Biolabs in Tucson, Arizona.
The product page identifies the testing laboratory and explains that the sample was analyzed using HPLC for purity and mass spectrometry for identity confirmation. The current COA can be viewed directly without creating an account or requesting the document from customer service.
Sports Technology Labs also provides some useful packaging details that other vendors do not emphasize. Its Selank is lyophilized in a sterile, UV-resistant glass vial with a tamper-evident seal. These features can help protect the material from light exposure and support batch traceability during storage.
The primary drawback is value. At $54.99 for 5 mg, the product costs approximately $11 per milligram before shipping or discounts. That is the highest regular cost per milligram among the three vendors.
Its current reported purity is also lower than the results or specifications displayed by BioInfinity and Limitless Biotech. That does not mean the product is unusable for every research application, but it is a meaningful difference that should be considered when comparing suppliers.
Orders are generally shipped within one business day, and domestic delivery usually takes approximately three to five business days. Free U.S. shipping begins at $149. The company currently ships only within the United States and allows unused products to be exchanged within 60 days.
Sports Technology Labs Pros
- Testing laboratory is clearly identified
- Batch-linked COA available without an account
- Both HPLC and mass-spectrometry testing used
- UV-resistant glass vial
- Tamper-evident packaging
- Longer 60-day exchange period for unused products
- Ships six days per week
Sports Technology Labs Cons
- Only 5 mg per vial
- Highest regular price per milligram
- Current batch reports 96.84% purity
- Does not ship internationally
- Free-shipping threshold is $149
Our Verdict: Sports Technology Labs is worth considering when transparent, easily verified testing and protective packaging are the highest priorities. However, its smaller vial, lower current purity result and higher cost per milligram prevent it from ranking above the first two companies.
How We Ranked the Best Selank Suppliers
We did not rank these companies based solely on which one offered the lowest price.
Research compounds must be evaluated using a broader set of criteria. A cheap product provides little value when the supplier does not establish its identity, disclose its batch information or provide independent analytical results.
Our rankings considered the following factors:
Independent Testing
Preference was given to companies that use an outside laboratory rather than relying entirely on internal quality-control claims.
Batch-Specific COAs
A useful Certificate of Analysis should correspond to the batch currently being sold. It should ideally identify the laboratory, testing date, batch number, analytical method and reported result.
Identity and Purity Testing
HPLC is commonly used to measure sample purity, while mass spectrometry can provide additional identity confirmation. A purity result by itself does not necessarily confirm that the material is the compound listed on the label.
Sterility and Endotoxin Testing
These are different from ordinary purity testing. Limitless Biotech receives additional credit for publishing separate sterility and endotoxin reports for its current N-Acetyl Selank batches.
Price and Vial Size
We considered the total purchase price, amount per vial, approximate price per milligram and available volume discounts.
Shipping and Customer Protection
Shipping speed, geographic availability, free-shipping thresholds and return or replacement policies were also included in the rankings.
Selank vs. N-Acetyl Selank
One of the most important differences in this comparison is that the companies are not all selling precisely the same compound.
BioInfinity and Sports Technology Labs list conventional Selank with the amino-acid sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro.
Limitless Biotech’s listing is labeled N-Acetyl Selank. Acetylation modifies the molecule by adding an acetyl group. Researchers should therefore avoid assuming that regular Selank and N-Acetyl Selank are interchangeable in every experiment.
The correct option depends on the compound specified by the research protocol. When reproducing an existing study, researchers should match the form, sequence and analytical standard used in the original work as closely as possible.
Researchers looking for general information about dosing ranges, administration methods, and frequency can review our complete Selank dosage guide.
What Should You Look for When Buying Selank for Research?
Before choosing a supplier, check whether the company provides a COA for the specific batch currently being shipped.
The report should ideally include:
- A batch or lot number matching the vial
- The date the sample was tested
- The name of the independent laboratory
- An HPLC purity result
- Mass-spectrometry identity confirmation
- Sterility or endotoxin results when required by the research
- Contact information that allows the report to be verified
Be cautious when a supplier publishes a generic example report that cannot be connected to the product being sold. A company-wide statement such as “all products are 99% pure” is less useful than a dated, batch-specific analytical result.
Frequently Asked Questions
What is the best place to buy Selank peptide?
Among the three companies evaluated, BioInfinity is our top overall selection. It currently offers a 10 mg vial with a batch-specific COA reporting 99.97% purity, clearly identified third-party testing and same-day U.S. shipping on qualifying orders.
Which Selank supplier has the lowest prices?
Limitless Biotech offers the most research material for the lowest listed price. However, its product is N-Acetyl Selank rather than conventional Selank, so the comparison is not completely equivalent.
Which company has the highest reported Selank purity?
BioInfinity displays the highest current batch result in this comparison at 99.97%. Limitless Biotech lists a specification of at least 99% for N-Acetyl Selank, while the current Sports Technology Labs batch reports 96.84%.
What is a Certificate of Analysis?
A Certificate of Analysis, commonly called a COA, is a laboratory report showing the results of tests performed on a sample. Depending on the report, it may include purity, chemical identity, sterility, endotoxin levels or other quality measurements.
A COA is most useful when it identifies the outside laboratory and corresponds directly to the batch number printed on the product.
Is Selank approved by the FDA?
Selank is not an FDA-approved medication in the United States. The FDA has stated that it lacks important safety information regarding Selank acetate administered to humans and has identified possible immunogenicity concerns for certain routes of administration.
The three companies reviewed on this page sell their products exclusively for laboratory research and label them as not intended for human or animal consumption.
Final Thoughts
Each of these companies offers a different advantage.
BioInfinity is our best overall selection because its 10 mg Selank combines a strong current purity result, batch-specific third-party testing, quantity discounts and fast U.S. shipping.
Limitless Biotech provides the best value and largest vial sizes, but researchers should recognize that it sells N-Acetyl Selank rather than conventional Selank.
Sports Technology Labs offers excellent testing transparency and packaging details, although its current 5 mg product is more expensive and has a lower reported purity result than the other choices.
For most researchers seeking conventional Selank, BioInfinity provides the strongest overall balance of purity, transparency, quantity and price.
Affiliate Disclosure: We may earn a commission when readers purchase through links on this page. This does not increase the price you pay or affect how the companies are evaluated.
References
- Zozulia AA, Neznamov GG, Siuniakov TS, et al. Efficacy and possible mechanisms of action of a new peptide anxiolytic Selank in the therapy of generalized anxiety disorders and neurasthenia. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(4):38-48. PMID: 18454096. https://pubmed.ncbi.nlm.nih.gov/18454096/
- Volkova A, Shadrina M, Kolomin T, et al. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Front Pharmacol. 2016;7:31. doi:10.3389/fphar.2016.00031. PMID: 26924987. https://pmc.ncbi.nlm.nih.gov/articles/PMC4757669/
- Kasian A, Kolomin T, Andreeva L, et al. Peptide Selank enhances the effect of diazepam in reducing anxiety in unpredictable chronic mild stress conditions in rats. Behav Neurol. 2017;2017:5091027. doi:10.1155/2017/5091027. PMID: 28280289. https://pmc.ncbi.nlm.nih.gov/articles/PMC5322660/
- Panikratova YR, Lebedeva IS, Sokolov OY, et al. Functional connectomic approach to studying Selank and Semax effects. Dokl Biol Sci. 2020;490(1):9-11. doi:10.1134/S001249662001007X. PMID: 32342318. https://pubmed.ncbi.nlm.nih.gov/32342318/
- Vyunova TV, Andreeva L, Shevchenko K, Myasoedov N. Peptide-based anxiolytics: the molecular aspects of heptapeptide Selank biological activity. Protein Pept Lett. 2018;25(10):914-923. doi:10.2174/0929866525666180925144642. PMID: 30255741. https://pubmed.ncbi.nlm.nih.gov/30255741/