Longevity Efficacy Testing
On ex vivo human skin and 3D skin models
Measure what an anti-aging or longevity claim actually needs: senescent cells, inflammation, collagen and hyaluronic acid, DNA damage, telomere length and DNA methylation, for finished products, extracts and supplements.
What is KronoLife's efficacy testing service?
KronoLife's efficacy testing service designs and runs studies that show whether a product or an active acts on the mechanisms of skin aging. Testing is done on living human skin kept outside the body (ex vivo human skin) and on 3D skin models, and read with aging biomarkers. The results support anti-aging and longevity claims at the level of evidence the study provides.
The service is built for skincare and supplement brands, contract manufacturers, extract and ingredient suppliers, and clinics developing their own products. It is most useful to teams that need numbers from human skin rather than only cell data or a supplier's technical sheet.
Why test on human skin models?
Cell assays show mechanism, but they cannot show what happens in the layered structure of real skin. Ex vivo human skin keeps the epidermis, dermis and extracellular matrix of living donor tissue, so collagen, hyaluronic acid, inflammation and cellular senescence are measured where they matter. 3D skin models, such as reconstructed human epidermis and full-thickness models, are more reproducible and suit pigmentation work and longer studies.
Each model answers a different question. Choosing the right one at the start saves both time and budget.
| Model | Question it answers | Strength | Limit |
|---|---|---|---|
| Cell assays (dermal fibroblasts, keratinocytes) | Mechanism, dose finding | Fast, low cost, many concentrations at once | No skin structure, no information on penetration |
| 3D skin models | Repeated application, pigmentation, irritation | Reproducible, long culture, pigmented versions available | Fewer cell types than real skin |
| Ex vivo human skin | Senescence, inflammation, collagen and damage in real adult skin | Full structure and cell types of donor skin | Limited culture window, donor-to-donor variation |
| Clinical study in volunteers | Effects consumers notice, safety in people | The strongest evidence for consumer claims | The most time and budget |
KronoLife designs and manages every study, working with partner laboratories in Thailand. Study design follows the evidence framework for substantiating longevity cosmeceutical claims, published in 2025 and co-authored by KronoLife's scientific lead.[1]
How to match endpoints to a claim
A good study starts from the claim you want to make, then works back to the endpoints and the model. This table is the starting point the team uses in a first call.
| Claim you want | Recommended endpoints | Model | Weeks |
|---|---|---|---|
| Wrinkles look reduced, skin looks firmer | Collagen I · laminin-5 · MMP-1 · skin thickness | Ex vivo human skin | 8–15 |
| Skin feels hydrated and plump | Hyaluronic acid | Ex vivo human skin | 8 |
| Reduces age-related inflammation | IL-6 · IL-8 · GDF-15 · TNF-α, with skin viability | Ex vivo human skin | 8 |
| Targets senescent cells (senolytic) | Senescence assay, with skin viability | Ex vivo human skin | 15 |
| Antioxidant, protects skin from pollution | ROS · 8-OHdG · UV, PM2.5 and blue-light panel | Ex vivo human skin | 8–15 |
| Cell-level anti-aging, biological age | Telomere length · DNA methylation | Ex vivo skin · 3D skin | 16–24 |
| Gentle, non-irritating | Skin viability (MTT/LDH) · cumulative irritation | Ex vivo human skin | 8–15 |
One claim usually needs two to four endpoints plus a viability check, to separate a real effect from an effect caused by damaged tissue. The team helps you choose the smallest set that is still strong enough to communicate.
Testing menu
| Area | Endpoints | Method | Weeks |
|---|---|---|---|
| Safety | Skin viability (a non-irritation screen) · cumulative irritation | MTT / LDH | 8 · 15 |
| Senescence | Senolytic activity (clearance of senescent cells) | Senescence assay | 15 |
| Inflammation | IL-6 · IL-8 · GDF-15 · TNF-α · MMP-1 (anti-collagenase) | ELISA | 8 |
| Extracellular matrix | Collagen I (ELISA) · collagen I, III, IV, V (staining) · hyaluronic acid (ELISA, IF) | ELISA · histology · IF | 8–15 |
| Oxidative stress | ROS reduction · DNA damage (8-OHdG) | Assay kits | 8 |
| Structure | Skin thickness · laminin-5 (anti-wrinkle) | Histology · IF | 15 |
| Exposome | Protection against UV, PM2.5, blue light, or all three | Marker panel | 15 |
| Aging clocks | Telomere length (ex vivo · 3D skin) · DNA methylation | qPCR · methylation array | 16 · 20 · 24 |
| Benchmarking | Against retinol, vitamin C, resveratrol or a marketed product | By marker | 8–32 |
| Procedures | Microneedle and mesotherapy products: efficacy and safety | By marker | 8–32 |
| Clinical follow-up | Longevity biomarkers in post-trial skin biopsies | By marker | 32 |
Some reagents need about 60 days to order, so tell us your launch date early.
What each group of endpoints tells you
Senescent cells
Senescent cells stop dividing but do not die, and release inflammatory factors into the tissue around them. They build up in aging skin. The most widely used marker is the enzyme SA-β-gal, which identifies senescent cells both in culture and in aging skin.[2] A senescence assay measures the senolytic activity of an active, and it is always read together with skin viability, to confirm that the cells removed are senescent cells and not healthy cells that were damaged.
Age-related inflammation
Chronic, low-grade inflammation that comes with age, often called inflammaging, is one of the hallmarks of aging.[3] On ex vivo human skin the team measures IL-6, IL-8, GDF-15 and TNF-α in the culture medium by ELISA, in about 8 weeks. One caveat matters: a cytokine can fall because the tissue is damaged and secreting less. That is why an MTT or LDH viability check is part of every study.
Collagen, hyaluronic acid and MMP-1
Collagen is the main structure that keeps skin firm, and hyaluronic acid holds water in the skin. The team measures collagen I by ELISA, stains collagen I, III, IV and V in tissue sections, and measures MMP-1, the enzyme that breaks collagen down. A good result can mean more collagen made or less collagen broken down, and each explains the mechanism in a different way.
Oxidative stress, DNA damage and the exposome
Reactive oxygen species (ROS) rise when skin is exposed to UV, blue light and pollution. The team measures ROS together with 8-OHdG, which shows damage to DNA. For claims about protecting skin from the environment, the exposome panel exposes the skin to UV, PM2.5 or blue light and reads several markers at once, in about 15 weeks.
Telomere length and aging clocks
Telomeres are the ends of chromosomes, and they shorten as cells divide. The team measures telomere length by qPCR[4] in ex vivo human skin (about 16 weeks) and 3D skin models (about 20 weeks). Epigenetic clocks based on DNA methylation estimate the biological age of cells, and a clock built for skin and blood suits ex vivo studies[5]; it takes about 24 weeks. Both endpoints change slowly, so they need replicates and a control run at the same time.
Testing supplements on human skin
Supplements can be studied on ex vivo human skin by adding them to the culture medium, which mimics exposure from inside the body instead of application to the skin surface. Few laboratories offer this. It suits beauty-from-within products that need data on human skin before investing in a clinical study. Powders, capsules and liquids are all accepted.
How results are reported: examples
The KronoLife internal data below show the reporting format used in every study: the endpoint, the model and the comparison, stated together. All results are against an untreated control.
- ZenoLase active on ex vivo adult human skin: collagen +94%, hyaluronic acid +484%, and age-related inflammation down 40 to 55%.
- ReverZase active on aged ex vivo human skin: collagen +103% and less DNA damage.
- ReverZase active on a pigmented 3D skin model (15 days): melanin −59%.
Data on all four actives are on the actives page.
How to write a claim from test results
A good claim says what was measured and in which model, for example "increased collagen in ex vivo human skin" or "helped maintain telomere length in a 3D skin model". A claim about what happens in the consumer's own skin needs a study in people. The 2025 framework recommends that longevity cosmeceuticals target established hallmarks of skin aging, be validated in clinical trials, and, where possible, include post-trial skin biopsies for aging biomarkers.[1]
Benchmarking against references the market knows, such as retinol, vitamin C or resveratrol, helps buyers and sales teams read the size of an effect straight away, provided both are tested in the same model and over the same period.
What you can send, and what you get back
- Samples: finished cosmetics, extracts (powder, viscous or liquid) and supplements (powder, capsule or liquid), plus any comparison product you want tested alongside.
- Deliverables: a short or full report, microscopy images, a presentation and infographic for your team, video or training on request, and support for grant proposals.
How a study runs
- Claim and brief What you want to say, for which product and market, under a non-disclosure agreement (NDA).
- Study design Endpoints, model, test concentrations, controls and benchmarks, and ordering the reagents.
- Samples Your product, and any comparison product.
- Testing 8 to 32 weeks, depending on the endpoints.
- Report Results that name the model, with guidance on claim wording.
Common questions
Can results on ex vivo human skin be used in marketing?
They can support a claim when the claim says what was tested and in which model, for example "tested on ex vivo human skin". A claim about effects in people needs a study in people, which can be planned as the next step.
How is ex vivo skin different from a 3D skin model?
Ex vivo skin is real human skin from a donor, with its full structure and cell types, and suits senescence, inflammation and collagen work. A 3D skin model is built from human cells in the laboratory; it is more reproducible and can be cultured longer, so it suits pigmentation and telomere work.
How long does a study take?
About 8 weeks for ELISA endpoints such as inflammation and oxidative stress, 15 weeks for senescence and the exposome panel, 16 to 24 weeks for telomere length and DNA methylation, and 32 weeks for post-trial biopsy analysis, plus about 60 days to order some reagents.
How many endpoints should we choose?
Match the endpoints to the claim. A firming claim usually needs collagen plus one inflammation marker; a senolytic claim needs a senescence assay plus a viability check. The team will suggest the smallest set that still holds up.
Can you test supplements?
Yes. Supplements are tested on ex vivo human skin through the culture medium, which mimics exposure from inside the body. Powders, capsules and liquids are accepted.
Can you benchmark against a competitor?
Yes. Benchmarking against retinol, vitamin C, resveratrol or a marketed product helps your team and your buyers read the size of the effect.
Is our formula kept confidential?
Yes. Every project starts under an NDA.
References
- Klinngam W, Chaiwichien A, Osotprasit S, Ruktanonchai U, Kanlayavattanakul M, Lourith N, Wongrakpanich A, Teeranachaideekul V, Iempridee T. Longevity cosmeceuticals as the next frontier in cosmetic innovation: a scientific framework for substantiating product claims. Front Aging. 2025;6:1586999. doi:10.3389/fragi.2025.1586999
- Dimri GP, Lee X, Basile G, Acosta M, Scott G, Roskelley C, et al. A biomarker that identifies senescent human cells in culture and in aging skin in vivo. Proc Natl Acad Sci U S A. 1995;92(20):9363-9367. doi:10.1073/pnas.92.20.9363
- López-Otín C, Blasco MA, Partridge L, Serrano M, Kroemer G. Hallmarks of aging: an expanding universe. Cell. 2023;186(2):243-278. doi:10.1016/j.cell.2022.11.001
- Cawthon RM. Telomere measurement by quantitative PCR. Nucleic Acids Res. 2002;30(10):e47. doi:10.1093/nar/30.10.e47
- Horvath S, Oshima J, Martin GM, et al. Epigenetic clock for skin and blood cells applied to Hutchinson Gilford Progeria Syndrome and ex vivo studies. Aging (Albany NY). 2018;10(7):1758-1775. doi:10.18632/aging.101508
Plan a longevity efficacy study
Tell us the product, the claim and your timeline. We will propose endpoints, models and a study plan.