48.1% more hair in 16 weeks.
Women using a 655nm red light device at home, against an 11.1% rise with an identical-looking sham device. Lanzafame et al. 2014 [2]
- Sham device · 16 weeks
- +11.1%
- Red light device · 16 weeks
- +48.1%
- Best density gain · 26 weeks
- +25.7 hairs/cm²
- Trials that improved (review)
- 10 of 11
Open any study. See exactly what was done and found.
Ordered from pooled evidence to single trials. Every number is from the published abstract, linked at the top of each study.
Tap a study to open it · swipe to browse
A systematic review and meta-analysis of randomized controlled trials of United States Food and Drug Administration-approved, home-use, low-level light/laser therapy devices for pattern hair loss: device design and technology
Lueangarun S, Visutjindaporn P, Parcharoen Y, Jamparuang P, Tempark TJ Clin Aesthet DermatolPubMed 34980962 ↗
- Systematic search to Jan 2020
- Only double-blind RCTs
- Sham comparator
- No conflicts declared
- P
- PopulationMen and women with pattern hair loss across seven trials of home-use devices cleared by the US FDA (32 such devices existed in Jan 2020).
- I
- InterventionHome-use low-level light or laser devices: combs and helmets, laser diodes alone or combined with LEDs.
- C
- ComparisonSham devices.
- O
- OutcomeChange in hair density, as a standardised mean difference (SMD).
“LLLT is potentially effective for PHL treatment.”
- Pools different devices, schedules and durations; the subgroup difference (laser diodes alone vs combined, p=0.043) is a comparison between trials, not within one.
- Covers FDA-cleared home devices only.
- Authors ask for long-term follow-up in severe hair loss and head-to-head device comparisons.
Cap 306 uses laser diodes alone, the subgroup with the largest pooled effect.
Low-level laser therapy as a treatment for androgenetic alopecia
Afifi L, Maranda EL, Zarei M, et al.Lasers Surg MedPubMed 27114071 ↗
- Two independent screeners
- Risk of bias assessed
- Medline, Google Scholar, Embase, 1960–2015
- No pooled statistics
- P
- Population680 patients with androgenetic alopecia: 444 men, 236 women.
- I
- InterventionLow-level laser therapy, across 11 studies.
- C
- ComparisonVaried by study: sham, baseline or other treatment.
- O
- OutcomeHair count or density; thickness and tensile strength; patient satisfaction.
“LLLT therapy seems to be a promising monotherapy for AGA and may serve as an effective alternative for individuals unwilling to use medical therapy or undergo surgical options.”
- The authors themselves advise caution in interpreting the findings.
- Patient satisfaction was positive but less striking than the measured results.
- Study designs varied; results are counted, not pooled.
Supports laser therapy for hair on its own, not only alongside medication.
Low-level laser therapy for the treatment of androgenic alopecia: a review
Darwin E, Heyes A, Hirt PA, Wikramanayake TC, Jimenez JJLasers Med SciPubMed 29270707 ↗
- PubMed, Embase, ClinicalTrials.gov
- Clinical trials only
- Narrative review
- P
- PopulationMen and women with androgenic alopecia in 13 clinical trials.
- I
- InterventionLow-level laser therapy, alone or with minoxidil or finasteride.
- C
- ComparisonBaseline or control, by trial.
- O
- OutcomeSignificant improvement in hair loss measures.
“LLLT appears to be a safe, alternative treatment for patients with androgenic alopecia.”
- A narrative review: trials are summarised, not combined statistically.
- Some trials compared with baseline rather than a control group.
- Optimal power and wavelength still to be established, the authors note.
Works alone or alongside minoxidil and finasteride in the trials reviewed.
Efficacy and safety of a low-level laser device in the treatment of male and female pattern hair loss: a multicenter, randomized, sham device-controlled, double-blind study
Jimenez JJ, Wikramanayake TC, Bergfeld W, Hordinsky M, Hickman JG, Hamblin MR, Schachner LAAm J Clin DermatolPubMed 24474647 ↗
- Randomised
- Double-blind
- Sham device
- Multicentre
- Blinded photo evaluator
- Hypothesis set before data collection
- P
- PopulationMen and women with pattern hair loss: 334 screened, 269 randomised, 225 analysed (103 men, 122 women).
- I
- InterventionHairMax Lasercomb (7, 9 or 12 beams), whole scalp, three times a week.
- C
- ComparisonIdentical sham device, issued in sealed packets.
- O
- OutcomeTerminal hair density per cm² at 16 and 26 weeks, from masked photographs.
“Our results suggest that low-level laser treatment may be an effective option to treat pattern hair loss in both men and women.”
- 44 participants (19 women, 25 men) were lost to follow-up.
- The device tested is a laser comb, used three times a week.
- Authors call for studies of long-term effects and of the best laser settings.
Same light family as Cap 306: red laser, 635–655nm.
The growth of human scalp hair in females using visible red light laser and LED sources
Lanzafame RJ, Blanche RR, Chiacchierini RP, Kazmirek ER, Sklar JALasers Surg MedPubMed 25124964 ↗
- Randomised
- Double-blind
- Identical sham
- Tattooed, masked photo site
- Blinded evaluator
- P
- Population47 women aged 18–60 with androgenic alopecia (Ludwig-Savin I-2 to II-2); 42 completed (24 active, 18 sham).
- I
- InterventionTOPHAT655 helmet: 21 laser diodes (5mW, 655±5nm) and 30 LEDs (655±20nm); 25 minutes every other day, 60 treatments.
- C
- ComparisonIdentical-looking helmet with incandescent red lights.
- O
- OutcomePrimary: percent increase in hair count from baseline at 16 weeks.
“LLLT of the scalp at 655 nm significantly improved hair counts in women with androgenetic alopecia at a rate similar to that observed in males using the same parameters.”
- Small: 42 women completed.
- The active helmet combined lasers and LEDs.
- Final hair counts did not differ significantly between groups (p=0.235); the change from baseline did (p<0.0001).
- 16 weeks only.
Close to Cap 306’s 650nm: 655nm red light, worn at home.
PICO: Population, Intervention, Comparison, Outcome. Statistics as reported in each abstract; p-values compare the treated group with the sham or control group. None of these studies tested a Somara device.
Personal experience, not clinical evidence. Not affiliated with Somara and no endorsement of Somara products. Quotes as published at the linked source; Joovv is a separate brand.
Longevity entrepreneur, founder of BlueprintBryan Johnson
“My hair is better at 49 than 29.”
- Reports
- Fuller hair than in his late twenties, from a combined routine: a laser cap alongside minoxidil, shampoo and serum.
- How often
- Laser cap for six minutes a day.
His haircare article, July 2026View original source ↗
Hair is where red light has its strongest evidence: trial after trial grew more hair than sham devices did. Somara Cap 306 is built on what worked best, laser diodes alone, with 306 of them at 650nm covering your whole scalp in 6 to 10 minutes a day.
Caveat · Trials used other brands’ devices. Results build over months of regular use.
