“Thicker fuller hair”
Fantastic products. Great quality. Highly recommend for anyone looking for thicker fuller hair!










Best for: a first trial to see how the tonic fits your routine. We recommend the Full Size for ongoing daily use. Early changes typically start after 6 to 8 weeks and keep building with consistent use.
Full SizeBest for: making the tonic part of your daily routine, and the best value per day. Early changes typically start to show after 6 to 8 weeks of daily use and build with consistent use.
Discovery SizeBest for: a first trial to see how the tonic fits your routine. We recommend the Full Size for ongoing daily use. Early changes typically start after 6 to 8 weeks and keep building with consistent use.
Choose your plan
Heads up: at this interval you may run out before your next bottle arrives, based on typical daily use.
New to PLU? Use code START10 at checkout for 25% off your first subscription order.
Heads up: at this interval you may run out before your next bottle arrives, based on typical daily use.
New to PLU? Use code START10 at checkout for 25% off your first subscription order.
Made in the USA of domestic and internationally sourced components.
AHK-Cu peptide is a synthetic copper peptide (Copper Tripeptide-3) made to support the appearance of fuller-looking hair. Our copper peptide serum pairs it at 1% concentration with 1% Acetyl Tetrapeptide-3.
Two clinically studied peptides, five total ingredients. No fragrance, no dyes, no botanical extracts. Both peptides verified at 1% by LC-MS in the finished bottle, at or above label claim, at the University of Illinois at Chicago. Most serums list 20 or 30 ingredients. We made one with everything you need, and nothing you don't.
Bring out the full potential of your hair by making this serum a part of your routine.
Ships directly to the USA. Also available on amazon.com domestically and in select international markets.
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Best for: a first trial to see how the tonic fits your routine. We recommend the Full Size for ongoing daily use. Early changes typically start after 6 to 8 weeks and keep building with consistent use.
Independently Tested
Every formula is tested by the Mass Spectrometry Core at the University of Illinois at Chicago. Actives verified by LC-MS in the finished bottle, at or above label claim. Heavy metals screened by ICP-MS. Reports published.
Verified reviews from PLU customers
Two peptide actives at 1% each, and three ingredients to carry them and keep them stable.
Sits at a full 1%, the same concentration as the Acetyl Tetrapeptide-3 beside it, and the concentration is confirmed by an outside lab.
It sits at the same 1% as the AHK-Cu, so neither active is a dusting on the label.
No oils and no silicones, which is why it absorbs in seconds and leaves nothing to rinse out.
It is the reason two or three drops spread across the part without leaving a film on the hair.
One preservative at a low level, the standard choice for water based cosmetics.
Water, Glycerin, Copper Tripeptide-3, Acetyl Tetrapeptide-3, Phenoxyethanol
Independently verified. See the test results.That's it.
Just 5 ingredients. And a lab report to prove it.
Five ingredients, each with a job
AHK-Cu, Acetyl Tetrapeptide-3, water, glycerin, phenoxyethanol. Every one earns its place.
Tested in the finished bottle
1% AHK-Cu and 1% Acetyl Tetrapeptide-3 verified by LC-MS at the University of Illinois at Chicago, at or above label claim. Heavy metals screened by ICP-MS.
Read the lab reportsMade in the USA, 30-day returns
Formulated and produced domestically, with 30-day returns.
AHK-Cu (Copper Tripeptide-3) is a synthetic variant of GHK-Cu. Both are copper peptides, but AHK-Cu swaps glycine for alanine in its amino acid chain (alanine-histidine-lysine vs glycine-histidine-lysine). Research on AHK-Cu has focused primarily on hair follicle applications.
We offer both GHK-Cu and AHK-Cu Hair Tonics so you can choose based on your preference. Same dual-peptide formula, same concentrations, same carrier system. The only difference is which copper peptide variant is used. Read our full AHK-Cu vs GHK-Cu comparison.
AHK-Cu copper peptide supports scalp's natural processes for fuller-looking hair and improved density appearance
Acetyl Tetrapeptide-3 helps improve how hair appears with consistent use and follicle support
Designed to help maintain healthy-looking scalp conditions and follicle appearance
Peptide concentrations formulated to match published research on hair appearance
The AHK peptide can be a powerful form of support for hair follicles. Studies suggest that AHK-Cu peptide may help promote the appearance of thicker, fuller-looking hair (when applied at clinical concentrations over time). The Acetyl Tetrapeptide-3 in our formula complements it. Most people see visible changes within 6-8 weeks of consistent daily use.
Some people also apply copper peptides for skin. AHK-Cu has early research interest there, but there’s just not as much data on that angle compared to GHK-Cu - which has decades of peer-reviewed study. Our GHK-Cu serum is the better fit for skin support. It pairs 1% GHK-Cu with Palmitoyl Tripeptide-1 and Palmitoyl Tetrapeptide-7. AHK peptide is built for your scalp.
Works on dry or damp hair. Create sections to expose scalp.
Dispense directly onto scalp. Use fingertips to massage into areas of concern
Do not rinse. Style hair as usual. Use morning and/or night.
Weeks 1-2
Scalp feels healthier with improved comfort
Weeks 3-4
Hair appears smoother with improved shine and less shedding
Weeks 6-8
Visible improvements in hair density and scalp health
Weeks 8-12
Hair appears noticeably thicker and fuller
Weeks 12+
Ongoing support for fuller, denser hair with daily use
Individual results may vary. Research on copper peptides, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, and Acetyl Tetrapeptide-3 noted visible improvements within study timeframes with consistent use of peptide complexes.
| GHK-Cu | AHK-Cu (This Product) | |
|---|---|---|
| Full Name | Copper Tripeptide-1 | Copper Tripeptide-3 |
| Amino Acids | Glycine, Histidine, Lysine | Alanine, Histidine, Lysine |
| Occurs Naturally | Yes (human plasma) | No (synthetic variant) |
| Research Focus | Skin + Hair | Primarily Hair |
| PLU Product | GHK-Cu Hair Tonic | AHK-Cu Hair Tonic |
Not better, just different. Both are copper peptides with the same histidine-lysine-copper structure. AHK-Cu (Copper Tripeptide-3) swaps glycine for alanine in the amino acid chain. GHK-Cu occurs naturally in human plasma and has decades of research across skin and hair. AHK-Cu is a synthetic variant with research focused primarily on hair follicle applications. We carry both here at PLU Laboratories, and you can always read our full AHK-Cu vs GHK-Cu comparison if you want to learn more.
Research suggests it may help support the appearance of hair density and fullness when applied consistently. Our formula uses 1% AHK-Cu paired with 1% Acetyl Tetrapeptide-3 at clinical concentrations. Five ingredients total, with visible changes showing up within 6-8 weeks.
Yes. Our formulation is free of parabens, sulfates, fragrance, and dyes. It's probably still worth patch testing on a small area first, as with any new scalp product. You may want to consult with a dermatologist before use if you have specific scalp concerns, too. However, there aren't really any known side effects so you can apply with peace of mind.
Right here at PLU Laboratories. Our AHK-Cu Hair Tonic comes in a 10 mL discovery size ($59.99) and a 30 mL full size ($119.99). We also carry copper peptides for hair in GHK-Cu formulations if you want to compare. Free shipping on every order.
Apply it directly to the scalp (not hair strands) since that’s where the formula needs to reach. Applying the copper peptide hair serum to strands will just leave you looking greasy without any actual impact on hair health. Massage it into the scalp for 30-60 seconds for best results. This may boost circulation and absorption. Focus on trouble areas.

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