The Studies
MAYDAY's efficacy claims come from independent laboratories, not internal testing. Four studies are published here in full, each with its protocol, method, and the untreated control it was measured against.
Efficacy at a glance
Independent laboratory results across the MAYDAY range.
99%
Prevention Shampoo
Head lice control — 2024 LSRN
100%
Prevention Shampoo (eggs)
Ovicidal when fully submersed — 2024 LSRN
95%
Daily Lice Prevention Conditioner
Stun & repel — 2024 LSRN
99%
Lice Treatment Hair Solution
Kills super lice & lice — 2025 LSRN
97%
Detangler Spray
Stun & repel — 2025 LSRN
100%
Furniture & Bedding Spray
Bed bug mortality at 24h — Microbe Investigations AG
Study 1 — 2024 Lice Prevention & Treatment
A three-arm “Proof of Claims” in-vitro study comparing MAYDAY's Prevention Shampoo, Fighting Conditioner and Treatment against the non-use of any lice product.
Efficacy of MAYDAY Lice Prevention & Treatment Products
Lice Solutions Resource Network (LSRN) · Katie Shepherd · Sterling IRB #12585
| Measure | Result | Untreated control |
|---|---|---|
| Prevention Shampoo — lice control | 99.05% | — |
| Prevention Shampoo — ovicidal (fully submersed) | 100% | — |
| Fighting Conditioner — stun & repel | 95.24% | — |
| Treatment vs Rid | 79.37% | Rid 44.44% |
The Treatment outperformed Rid by a factor of nearly two in the same assay, and the Prevention Shampoo was fully ovicidal when eggs were submersed.
Study 2 — 2025 Super-Lice Product Line
A three-phase, four-arm study testing the MAYDAY line against DNA-confirmed “super lice,” with genetic resistance testing performed by Seoul National University.
MAYDAY Product-Line Efficacy Against DNA-Confirmed Super Lice
LSRN · Katie Shepherd · DNA testing: Dr. Ju Hyeon Kim, Seoul National University
| Measure | Result | Untreated control |
|---|---|---|
| Reformulated Shampoo — mortality vs super lice | 100% | — |
| Reformulated Treatment — mortality vs super lice | 100% | — |
| Detangler Spray — stun & repel | 97% | — |
| Furniture & Bedding Spray — lice | 92% | — |
| Egg-hatch failure (3-min exposure + rinse) | 73.3% | Generic 43.3% |
100% of the lice tested carried the kdr pesticide-resistance mutation at all three loci — verified super lice. MAYDAY products were then tested directly against them. Mortality figures are reported as 99% on product pages to allow for real-world variability.
Study 3 — Furniture & Bedding Spray
Beyond its 92% head-lice protection, the Furniture & Bedding Spray was independently tested against bed bugs by Microbe Investigations AG, a spin-off of ETH Zürich.
Furniture & Bedding Spray — Bed Bug Knockdown & Mortality
Microbe Investigations AG (ETH Zürich spin-off) · EPA OCSPP 810.3900 direct-spray method
| Measure | Treated (MAYDAY) | Untreated control |
|---|---|---|
| Knockdown (under 10 minutes) | 100% | 0% |
| Mortality at 24 hours | 100% | 0% |
Every treated bed bug was knocked down within minutes and all were dead at 24 hours, while the untreated control group showed no effect — a clean, properly controlled result.
Study 4 — Pest Control Spray
The Pest Control Spray was tested for repellency against two common household pests — Argentine ants and house spiders — by Snell Scientifics, an independent entomology laboratory in Meansville, Georgia.
Pest Control Spray — Crawling Insect Repellency
Snell Scientifics, LLC · Todd Smith · Test Method 310 (non-GLP)
| Measure | Treated (MAYDAY) | Untreated control |
|---|---|---|
| Argentine ant repellency (30 min – 4 hr) | 83–93% | 33–55% |
| House spider repellency (30 min – 4 hr) | 70–80% | 43–53% |
Read the control column. On untreated panels insects distributed roughly evenly across both halves, as expected with no repellent present. On MAYDAY-treated surfaces they moved decisively away and stayed away across every observation from 30 minutes to 4 hours. The gap between the two columns is the repellent effect.
Important context
All efficacy figures above are from independent laboratory (in-vitro) studies, not in-vivo clinical trials on humans. Studies were sponsored by Omniche Consumer Products Co. and conducted independently by the named testing organizations under the protocols noted. The Pest Control Spray repellency study was conducted by Snell Scientifics under sound scientific principles as a non-GLP study, meaning it does not comply with Good Laboratory Practice standards under 40 CFR 160. MAYDAY products are not FDA-regulated drugs; ingredients meet FDA GRAS guidelines. Some figures are reported conservatively (for example “99%”) to account for real-world variability.