AHK-Cu vs GHK-Cu: Which Peptide Is Better for Skin?
GHK-Cu wins this on evidence. It has human wound and skin data behind it. AHK-Cu has one unreplicated dish study and no human trial at all. Use GHK-Cu…
- AHK-Cu
- GHK-Cu
Best Interventions for Skin Health, Ranked by Evidence
Every intervention Outliyr has scored for skin health, ranked by its BioHarmony score for this use case rather than its overall rating. The number beside each name is how well that one thing works for skin health; the tier beside it is what it is worth once safety, cost and effort are counted across everything else.
54 of 118 evaluated interventions score 3.0+ out of 10 for skin health · 13 comparisons
Ranked for Skin Health
Category
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GHK-Cu
Topical GHK-Cu keeps its v0 score because cosmetic skin remains the strongest lane: wrinkle, firmness, collagen, elastin, keratinocyte, and barrier mechanisms converge in human and ex vivo evidence. Use Mulder 1994 for…
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Red Light Therapy
Wunsch 2014 found wrinkle reduction and collagen-density improvement after repeated red and near-infrared sessions. This is one of the cleaner consumer-relevant use cases because the target tissue is superficial and reachable. The…
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Glycine
Holecek 2025 anchors the most relevant signal. Glycine fits skin beauty because glycine participates in sleep signaling, glutathione, collagen, methylation, and nervous-system balance, depending on the endpoint. The score stays bounded because…
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Astaxanthin
AAD reports AAD skin-cancer prevention guidance emphasizes SPF, shade, and UV avoidance; no astaxanthin endorsement surfaced. The score stays conditional because Astaxanthin still needs better outcome data for this exact use case.…
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Melanotan I (Afamelanotide)
Melanotan I scores highest for skin-beauty because afamelanotide reliably increases pigmentation in human studies and improves repigmentation when paired with narrowband UV-B. The strongest cosmetic-adjacent clinical signal is the generalized vitiligo trial…
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Lactoferrin
Skin-beauty score is driven mostly by acne, not collagen or photoaging. Kim 2010 tested lactoferrin-enriched fermented milk for acne, Chan 2017 tested lactoferrin with zinc and vitamin E in mild-to-moderate acne, and…
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TB-500 (Thymosin Beta-4 Fragment)
Skin-beauty is a secondary extrapolation from wound healing, angiogenesis, matrix remodeling, and anti-inflammatory pathways. Philp 2004 reported wound-healing and hair-follicle development effects in animal work, but no human cosmetic RCT supports TB-500.…
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Collagen Peptides
Proksch 2014 supports skin elasticity, Proksch 2014 wrinkle paper supports dermal matrix effects, but Myung 2025 weakens confidence in high-quality non-industry subgroups. That makes Collagen Peptides more defensible when skin beauty is…
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Infrared Sauna
Kihara 2002 makes the claim plausible but incomplete. The existing rationale points to this narrower claim: Infrared sauna may improve skin appearance through blood flow, sweating, and sebaceous activity. Near-infrared systems overlap…
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Hyaluronic Acid
Sun 2022 pooled 4 oral RCTs (196 adults) and found a small but significant hydration gain (SMD +0.40, p=0.007), and Hsu 2021 showed 120 mg/day for 12 weeks improved wrinkle scores, stratum…
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Melanotan II
Melanotan II has a clear tanning effect, but the skin-beauty score is capped by safety and regulatory uncertainty. Human melanotropin trials showed tanning from subcutaneous administration, and the early MT-II pilot reported…
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Rapamycin
Harrison 2009 anchors the most relevant signal. Rapamycin fits skin beauty when mTORC1 modulation, autophagy, immune aging, or senescence biology is the actual target. The score stays bounded because human longevity endpoints…
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Senolytics
Senescent fibroblast clearance fits skin-aging theory, but no human F+Q skin-aging outcome trial was verified in the audit. The score stays bounded because Senolytics evidence for skin beauty can depend on age,…
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Essential Amino Acids
Hagiyama 2024 reports 12 RCTs; 622 patients; low-certainty improvement in patient-reported outcomes and very-low-certainty strength signal after lower-limb surgeries. Wittholz 2024 points in the same direction, but route, dose, baseline status, and…
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Molecular Hydrogen
Dhillon 2024 reports 25-article systematic review; mixed preliminary clinical evidence, heterogeneity, and need for stronger trials. Zhou 2024 points in the same direction, but route, dose, baseline status, and outcome tracking decide…
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Vitamin C (Ascorbic Acid)
Vitamin C's role here is mechanistically certain even where the cosmetic trial base is thin. As the essential cofactor for prolyl and lysyl hydroxylase, it is required for stable collagen cross-linking, which…
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Spermidine
Eisenberg 2016 makes the claim plausible but incomplete. The existing rationale points to this narrower claim: Autophagy gives a coherent skin-aging rationale, but verified human dermatology evidence is much narrower than the…
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C60 (Buckminsterfullerene)
C60 (Buckminsterfullerene) was applied topically in squalane for eight weeks to 23 Japanese women, and the study reported a measurable reduction in wrinkle depth without severe adverse events. Because the trial was…
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Ca-AKG (Calcium Alpha-Ketoglutarate)
Demidenko 2021 supports direction more than certainty. The existing rationale points to this narrower claim: Mechanism via fibroblast epigenetic remodeling is possible, but human skin evidence is anecdotal only. That does not…
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Methylene Blue
Rodriguez 2016 anchors the strongest signal. The existing rationale points to this narrower claim: Skin-beauty use stays neutral-positive because topical dye and antimicrobial history do not equal cosmetic anti-aging proof. Procedure and…
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Hyperbaric Oxygen Therapy
Wound healing and radiation-injured tissue support skin repair, but beauty and anti-aging skin claims are weaker than medical wound care. Yang 2024 supports adjunctive wound healing in selected patients. Cosmetic skin rejuvenation,…
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Zone 2 Cardio
Zone 2 may improve skin appearance through circulation, lower inflammation, better glucose control, and sleep. It is not a direct cosmetic intervention like photobiomodulation, topical retinoids, or collagen-stimulating procedures.
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Polyphenols (Dietary)
Some polyphenols show photoprotective and elasticity signals in small trials, and the antioxidant mechanism is plausible, but dedicated outcome evidence for the dietary class is limited and not a sunscreen substitute.
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Shilajit
Neltner 2022 reported increased serum pro-c1alpha1, a type 1 collagen synthesis marker, after 8 weeks. Skin outcomes themselves were not measured.
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Whole-Body Vibration
Cutaneous vasodilation is acute, not durable. Skin-tightening claims are not well-supported and itch can occur after WBV exposure.
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Metformin
AMPK and glycation mechanisms can support skin-aging hypotheses, but human cosmetic endpoint trials are not established. This remains preclinical or indirect through better glycemic control.
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Ergothioneine
Ergothioneine appears in cosmetic antioxidant formulations and protects skin cells from oxidative and UV stress in lab models, but oral skin-outcome human trials are sparse.
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Berberine
Topical and antimicrobial traditions create a plausible acne and skin-inflammation angle, but oral berberine has thin direct evidence for skin-beauty outcomes. Users with insulin resistance may see indirect acne benefit through glucose…
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Taurine
Taurine has antioxidant and osmoregulatory mechanisms that could matter for skin biology, but direct skin-beauty RCTs are sparse. This is not a primary reason to use taurine.
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Traditional Sauna (Finnish Dry-Heat)
Sauna increases skin blood flow and sweating, which some users feel improves skin tone, but there is no robust outcome evidence for skin appearance or aging from traditional dry sauna. This stays…
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BPC-157
Wound healing and collagen synthesis support skin repair, especially in injury or wound contexts. It is not a cosmetic skin intervention with human photoaging trials, unlike red light therapy or retinoids.
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Thymosin Beta-4 (Tβ4)
Skin benefits beyond wound healing have no dedicated human Tβ4 trial. The mechanism of accelerated keratinocyte migration and angiogenesis is plausible for post-procedure or cosmetic-repair use, and the RGN-137 wound program shows…
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Omega-3
Skin evidence is modest and heterogeneous, strongest for inflammatory skin conditions rather than cosmetic beauty. Effects are not comparable to topical retinoids or light-based dermatology.
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Ketogenic Diet
Skin response is mixed. Some acne-prone users improve through lower insulin and IGF-1 signaling, while others develop prurigo pigmentosa or worsen skin quality through low fiber, low micronutrient variety, or endocrine stress.…
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Glutathione (GSH)
The evidence does not match the hype. Weschawalit 2017, the headline oral skin RCT, found the melanin index only trended lower without reaching significance; the one significant skin finding was reduced wrinkles.…
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Quinton Marine Plasma (Seawater Minerals)
A 33-person uncontrolled before-and-after in atopic dermatitis (Hataguchi 2005) reported skin improvement and shifted mineral status, but the absence of a control arm makes it weak evidence.
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Curcumin
Only pilot-sized trials exist, mostly topical, for conditions like psoriasis where a niosomal curcumin pilot suppressed inflammatory gene expression. Underpowered and not pooled into an effect size. Promising but early.
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Resveratrol
Skin-beauty claims are stronger for topical antioxidant products than oral capsules. Oral resveratrol faces low parent-compound bioavailability and no strong human skin-aging endpoint trial comparable to device-based photobiomodulation or topical retinoids. Szymkowiak…
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TRT (Testosterone Replacement Therapy)
TRT is not a skin-beauty intervention. Androgen exposure can increase oiliness and acne, especially in DHT-sensitive users or high-peak injection protocols. Any collagen or body-composition benefit is secondary.
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CJC-1295
GH/IGF-1 axis promotes collagen synthesis and skin thickness; community reports improved skin quality. This remains indirect because Teichman 2006 measured hormone response, not skin endpoints.
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Tirzepatide
Tirzepatide has no direct skin quality trial. Weight loss may improve obesity linked inflammation and insulin related skin issues for some users. Rapid fat loss can also worsen facial volume loss, skin…
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Thymosin Alpha-1
Skin benefit is indirect through wound and immune regulation. There is no acne, collagen, photoaging, or hair-follicle human evidence comparable to dermatologic photobiomodulation or retinoid trials.
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Colostrum
Skin-beauty claims are mostly anecdotal. Growth-factor and dairy-bioactive mechanisms are possible at the gut and immune level, but direct human skin RCTs for oral bovine colostrum remain limited.
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NMN (Nicotinamide Mononucleotide)
Skin-aging evidence is limited and not central to the verified NMN human base. Current stronger citations are metabolic and NAD+ trials, not dermatology endpoints.
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Vitamin D3 + K2
Thin evidence base for D3+K2 on skin endpoints. VDR expression in keratinocytes is well-documented but no robust RCT exists for D3 supplementation on skin barrier, photoaging, or pigmentation. Topical D3 preparations (calcipotriol)…
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Spirulina
Carotenoid and antioxidant content gives a plausible skin rationale, but human skin-outcome trials are minimal.
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Coenzyme Q10 (CoQ10 / Ubiquinol)
Topical CoQ10 has limited antioxidant skin-aging data, but oral CoQ10 for skin lacks strong human outcome trials; mostly mechanistic optimism.
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KPV (Lys-Pro-Val)
Alpha-MSH fragments have documented anti-inflammatory skin effects, and Sung 2025 found KPV reduced PM10-induced inflammatory signaling in keratinocyte and 3D skin models, but direct human dermatology evidence is absent.
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Ashwagandha
Skin-beauty support is indirect. Stress and inflammation can worsen skin quality, and antioxidant pathways may help, but the audit found no dedicated dermatology RCT to elevate this score. Use red light therapy,…
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Fucoidan (Brown Seaweed Polysaccharide)
Topical and cosmetic uses are preclinical; no oral human skin-outcome evidence.
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Semaglutide
Rapid fat loss can create loose skin and facial volume loss; semaglutide is not a collagen or skin-quality intervention.
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Tesamorelin
GH/IGF-1 can influence dermal thickness and collagen turnover, but tesamorelin has no strong skin-aging RCT evidence. Any skin benefit is indirect and should not drive use.
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Pine Pollen
Antioxidant content gives a plausible cosmetic rationale, but there is no human skin-outcome study for oral or topical pine pollen.
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C15 (Pentadecanoic Acid)
No human C15:0 supplementation trial has measured wrinkles, skin hydration, transepidermal water loss, acne, sebum, or validated dermatology quality scores. Robinson 2024 (Robinson 2024) did not include skin endpoints. The membrane-lipid hypothesis…
Nothing matches those filters.
What each one costs
Monthly out-of-pocket cost at the most accessible legitimate channel, at the dose the score was given for. 16 of 54 are not priced yet; those cells are left blank rather than guessed.
| Intervention | Monthly cost | At dose | How you get it |
|---|---|---|---|
| GHK-Cu | $30–$100 | 0.5-3% topical serum or cream | Over the counter |
| Red Light Therapy | $17–$43 | 10-20 min at 6-12 inches, full chest/face/back rotation | Over the counter |
| Glycine | $2–$3 | 3 g oral glycine | Over the counter |
| Astaxanthin | Not priced yet | ||
| Melanotan I (Afamelanotide) | $38–$129 | Variable, microgram-to-milligram loading cycles, not clinically validated | Grey market |
| Lactoferrin | $25–$50 | 250-300 mg apolactoferrin | Over the counter |
| TB-500 (Thymosin Beta-4 Fragment) | Not priced yet | ||
| Collagen Peptides | $8–$40 | 2.5-10 g hydrolyzed collagen peptides | Over the counter |
| Infrared Sauna | $36–$73 | 55-60 degrees C, 20-30 min | Over the counter |
| Hyaluronic Acid | Not priced yet | ||
| Melanotan II | $25–$55 | Variable | Research use only |
| Rapamycin | $15–$50 | 3 mg | Prescription |
| Senolytics | Not priced yet | ||
| Essential Amino Acids | Not priced yet | ||
| Molecular Hydrogen | Not priced yet | ||
| Vitamin C (Ascorbic Acid) | Not priced yet | ||
| Spermidine | $40–$90 | 1-3 mg/day oral WGE | Over the counter |
| C60 (Buckminsterfullerene) | Not priced yet | ||
| Ca-AKG (Calcium Alpha-Ketoglutarate) | $15–$30 | 1 g/day generic Ca-AKG oral | Over the counter |
| Methylene Blue | $13–$40 | 0.5-5 mg oral | Over the counter |
| Hyperbaric Oxygen Therapy | $3,000–$6,000 | 2.0 ATA for 90 minutes with air breaks | In clinic |
| Zone 2 Cardio | Not priced yet | Over the counter | |
| Polyphenols (Dietary) | Not priced yet | ||
| Shilajit | $25–$50 | 500 mg purified shilajit | Over the counter |
| Whole-Body Vibration | $50–$100 | 30 Hz, roughly 0.3g, 10-20 min standing | Over the counter |
| Metformin | $4–$30 | 500 mg with dinner for 1 week, then 500 mg twice daily for 1 week, then increase by 500 mg/week toward 1000 mg twice daily as tolerated | Prescription |
| Ergothioneine | Not priced yet | ||
| Berberine | $15–$25 | 500 mg berberine HCl three times daily with meals | Over the counter |
| Taurine | $3–$10 | 1-3 g, 30-60 minutes before sleep | Over the counter |
| Traditional Sauna (Finnish Dry-Heat) | $50 | 15 to 20 minutes at 80 to 100 C | Over the counter |
| BPC-157 | $40–$80 | 250 to 500 mcg SC 1 to 2x/day near injury site | Grey market |
| Thymosin Beta-4 (Tβ4) | Not priced yet | ||
| Omega-3 | $20–$40 | 1-2 g/day combined EPA+DHA | Over the counter |
| Ketogenic Diet | $100 | Standard keto, 40-50 g total carbohydrate/day | Over the counter |
| Glutathione (GSH) | $20–$45 | 1,000 mg/day | Over the counter |
| Quinton Marine Plasma (Seawater Minerals) | Not priced yet | ||
| Curcumin | $15–$40 | 500 mg curcuminoids | Over the counter |
| Resveratrol | Not priced yet | ||
| TRT (Testosterone Replacement Therapy) | $50–$300 | Clinician-selected formulation at the lowest dose likely to restore physiologic testosterone | Prescription |
| CJC-1295 | $80–$200 | 1-2 mg subcutaneous | Grey market |
| Tirzepatide | $299–$449 | 2.5 to 5 to 7.5 to 10 to 12.5 to 15 mg | Prescription |
| Thymosin Alpha-1 | $100–$400 | 1.6 mg subcutaneous | Prescription |
| Colostrum | $60–$80 | 20 g/day powder, split AM/PM if tolerated | Over the counter |
| NMN (Nicotinamide Mononucleotide) | $40–$100 | 500 mg/day oral | Over the counter |
| Vitamin D3 + K2 | Not priced yet | ||
| Spirulina | $10–$25 | 1 to 4.5 g/day | Over the counter |
| Coenzyme Q10 (CoQ10 / Ubiquinol) | $15–$40 | 100-200 mg/day | Over the counter |
| KPV (Lys-Pro-Val) | $40–$100 | 250-500 mcg/day oral | Grey market |
| Ashwagandha | $15–$30 | 300 mg KSM-66 with breakfast and 300 mg with dinner | Over the counter |
| Fucoidan (Brown Seaweed Polysaccharide) | Not priced yet | ||
| Semaglutide | $199–$349 | 0.25 mg weeks 1 to 4, 0.5 mg weeks 5 to 8, 1.0 mg weeks 9 to 12, 1.7 mg weeks 13 to 16, 2.4 mg week 17 onward | Prescription |
| Tesamorelin | $250–$500 | 2 mg subcutaneous daily in the evening | Prescription |
| Pine Pollen | $20–$45 | 5 to 10 g powder per day | Over the counter |
| C15 (Pentadecanoic Acid) | $40–$50 | 200 mg/day | Over the counter |
Comparisons that judge skin health
Head-to-head reports and category rankings that name a winner on this use case.
BPC-157 vs KPV: Which Peptide Is Better for Gut Healing?
BPC-157 for structural repair, KPV for inflammation you cannot afford to stimulate. BPC-157 scores gut health 9.0–9.5/10 against KPV's 7.0–7.5/10 and wins nearly every other row, because it…
- BPC-157
- KPV
Colostrum vs Collagen Peptides: Which Should You Buy?
These two get sold as the same thing, a scoop for gut and skin, and they share almost no mechanism. Colostrum is a gut and immune product: gut…
- Colostrum
- Collagen Peptides
HBOT vs Red Light Therapy: Which Is Better for Recovery?
Buy the panel. Red light therapy scores 7.5–8.0/10 against HBOT's 5.5–6.0/10, costs $17 to $43 a month against $3,000 to $6,000, and does not lose a single use…
- Hyperbaric Oxygen Therapy
- Red Light Therapy
Melanotan I vs Melanotan II: Which Peptide Is Safer for Tanning?
Melanotan I is the safer tanning peptide and it scores higher, 6.0–6.5/10 against 4.5–5.0/10. Both darken skin through the same receptor. Melanotan II hits three more receptors, which…
- Melanotan I
- Melanotan II
Sermorelin vs Ipamorelin: Which Peptide Is Better for Fat Loss?
Start on sermorelin. Ipamorelin scores higher overall, yet sermorelin wins thirteen of the sixteen shared use cases and it is the one an anti-aging clinic actually prescribes. Ipamorelin…
- Sermorelin
- Ipamorelin
Lactoferrin vs Colostrum: Which Is Better for Immunity?
Lactoferrin scores 7.0–7.5/10 against colostrum's 6.5–7.0/10, and lactoferrin is one protein inside colostrum. Buy lactoferrin when iron handling, acne or H. pylori is the target, at $25 to…
- Lactoferrin
- Colostrum
PT-141 vs Melanotan II: Which Peptide Is Better for Libido?
PT-141 scores 5.0–5.5/10 and melanotan II 4.5–5.0/10, and both land in the neutral tier. PT-141 is the defensible one. It targets the brain receptor that drives desire, it…
- PT-141
- Melanotan II
Rapamycin vs Metformin: Which Is Better for Longevity?
Metformin scores 6.5–7.0/10 and rapamycin 6.5–7.0/10, which settles nothing. Rapamycin owns the aging-biology rows: longevity 8.0/10, autophagy 8.5/10, senescence 7.8/10, plus replicated mouse lifespan data. Metformin owns everyday…
- Rapamycin
- Metformin
Red Light Therapy vs Infrared Sauna: Which Should You Buy?
Red light therapy scores 7.5–8.0/10 and infrared sauna 7.0–7.5/10, so buy the panel first. It costs less, targets skin, hair, joints and recovery directly, and carries higher evidence…
- Red Light Therapy
- Infrared Sauna
Taurine vs Glycine: Which Amino Acid Should You Take?
Taurine scores 8.0–8.5/10 and glycine 7.5–8.0/10, close enough that the overall numbers pick nothing. Taurine wins cardiovascular and metabolic endpoints outright. Glycine wins antioxidant, skin and connective tissue.…
- Taurine
- Glycine
Traditional Sauna vs Infrared Sauna: Which Should You Buy?
Traditional sauna scores 7.5–8.0/10 and infrared 7.0–7.5/10. Infrared actually scores higher on 20 of the 23 use cases both are rated on. Buy traditional anyway if hard outcomes…
- Traditional Sauna
- Infrared Sauna
Questions about skin health
What scores highest for skin health?
GHK-Cu, at 9.0–9.5 out of 10 for skin health. Topical GHK-Cu keeps its v0 score because cosmetic skin remains the strongest lane: wrinkle, firmness, collagen, elastin, keratinocyte, and barrier mechanisms converge in human and ex vivo evidence.
What is the cheapest thing that works for skin health?
Of the top-scoring options, Glycine is the least expensive at about $2 a month, scoring 7.5–8.0 out of 10 for skin health.
What should I be careful with for skin health?
C60 (Buckminsterfullerene) scores 5.5–6.0 out of 10 for skin health but only 4.0–4.5 overall, landing in the caution tier once safety, side effects, cost and effort are counted.
How many interventions has Outliyr scored for skin health?
54 of the 118 interventions evaluated for skin health score 3.0 out of 10 or better, which is the cut-off for appearing on this page.
