Challenge Protocol · Skincare + Lifestyle
The 30 Day Glow Up Challenge: Week-by-Week Protocol
A 30 day glow up challenge is a structured daily system that combines skincare, training, nutrition, grooming, and sleep into one protocol. Follow it consistently and you will see measurable skin texture improvement, a maintained appearance, and early training adaptations by Day 30, with the compounding transformation visible at Day 60 to 90.
This is a week-by-week protocol for anyone who wants a structured, evidence-grounded approach to looking and feeling better in 30 days. It covers every variable that actually moves the needle: skincare actives with real clinical data, the supplement stack that cortisol and collagen research supports, resistance training, sleep habits, and grooming. Each week layers on the previous one, adding complexity only after the prior layer is locked in. By Day 30, you will have a complete system running on autopilot and visible evidence of where you started.
// What's in this guide
01Before you start: Day 0 setup
Preparation is what separates a 30-day challenge that produces lasting change from one that fizzles after a week. Do these on Day 0, before anything else.
Take baseline photos
Non-negotiable. You need objective evidence of your starting point because the mirror lies, you adapt to gradual daily change and stop seeing it. Take photos in consistent natural light, from three angles: front-facing, 45-degree left, 45-degree right. After cleansing, before any products. Store them somewhere you will not delete them. Compare at Day 15 and Day 30. For a complete photo tracking protocol, see the before and after tracking guide.
Get your gear
The minimum skincare kit for Week 1:
- Gentle hydrating cleanser, such as MAXXING Fresh Start
- Niacinamide serum (4 to 5%), such as MAXXING Clear Dominance
- Ceramide moisturizer, such as MAXXING Damage Control
- SPF 30 to 50 (a MAXXING SPF is coming soon)
You will add MAXXING Glow GHK-Cu Copper Peptide Serum in Week 2. The full protocol stack is available in the GlowMaxxing collection, and the Stack Builder assembles your exact protocol at the best price.
Set your training schedule
Block 3 to 4 training sessions per week in your calendar right now. Resistance training is required; cardio is supplementary. A gym is not required for the first 30 days. Bodyweight circuits (push-ups, pull-ups, squats, lunges, dips) provide sufficient stimulus. The key variable is consistency, not equipment.
Stock your kitchen
You need protein-rich food accessible every day: eggs, chicken, fish, Greek yogurt, whey protein. Target 1.6 to 2.2g of protein per kg of bodyweight. Have collagen peptides and creatine ready for Week 2.
Day 0 is about removing friction. When Day 1 arrives, products should be on the bathroom counter, gym sessions blocked, protein in the fridge. Decision fatigue kills challenges. Eliminate it before you start.
02Week 1: build the foundation
Skincare (Tier 1 protocol)
- AM: Cleanser, niacinamide serum, moisturizer, SPF
- PM: Cleanser, moisturizer
- Four products. Under 5 minutes per routine. The goal this week is doing this twice every single day without exception, not perfecting product choice.
Niacinamide at 4 to 5% is the right concentration for this stage. A 2006 double-blind controlled trial found it significantly reduced sebum production and oiliness within 2 to 4 weeks of twice-daily use.2 A broader 2005 review documented improvements in hyperpigmented spots, red blotchiness, yellowing, and fine-line appearance across multiple randomized trials.3 You can expect visible oil control and texture improvement by end of Week 1 to early Week 2.
Training
- 3 to 4 resistance training sessions, full body or upper/lower split
- Compound movements: squat, bench press, deadlift, overhead press, rows
- Moderate intensity, establish form and consistency before loading
- If new to training: bodyweight circuits (3 rounds of 10 push-ups, 10 squats, 10 lunges, 5 pull-ups or rows, 30-second plank)
Body composition improvement is the single highest-leverage physical change for facial aesthetics. For a structured training progression beyond the first 30 days, see the complete looksmaxxing guide.
Nutrition
- Hit your protein target: 1.6 to 2.2g per kg bodyweight daily
- 2 to 3 liters of water per day. Hydration affects skin quality directly and measurably.
- Cut or significantly reduce alcohol. It dehydrates skin, elevates cortisol, and disrupts sleep architecture.
- No calorie tracking yet. Just protein and hydration.
Sleep
- Consistent bedtime and wake time, same every day including weekends
- Target 7 to 9 hours. Growth hormone secretion and skin cellular repair peak during deep sleep.6
- No screens 30 minutes before bed. Blue light suppresses melatonin and delays sleep onset.
Sleep deprivation has measurable cosmetic effects. A 2013 study found sleep-deprived faces were rated as having darker under-eye circles, paler skin, more wrinkles, and droopier mouth corners by independent observers.7 A 2015 study found poor sleepers had 30% worse skin barrier recovery and higher intrinsic aging scores than good sleepers.8 Sleep is not a soft variable.
Day 7 check-in
- 6 to 7 consecutive days of twice-daily skincare completed
- 3 to 4 training sessions completed
- Slightly less oily skin already, niacinamide begins working in 3 to 7 days
- If you missed days, do not reset. Pick up immediately.
03Week 2: add active ingredients and supplements
Skincare (Tier 2 upgrade)
- AM: Cleanser, niacinamide, GHK-Cu copper peptide serum, moisturizer, SPF
- PM: Cleanser, GHK-Cu copper peptide serum, moisturizer
- Start GHK-Cu every other day for the first 3 to 4 days, then move to daily by end of week.
GHK-Cu (Copper Tripeptide-1) is a naturally occurring peptide your body already makes. It signals collagen production, accelerates tissue repair, and suppresses visible inflammation. A randomized double-blind trial found it produced a 55.8% reduction in measured wrinkle volume after 8 weeks.1 MAXXING Glow is formulated at 0.2% GHK-Cu as a single disclosed active, which is within the clinically effective range for daily cosmetic use. Niacinamide and GHK-Cu are pH-compatible and work well together in the same routine. Read the full GHK-Cu guide for the complete clinical picture, or see the looksmaxxing skincare protocol for layering strategy.
Supplements (launch the stack)
- Creatine monohydrate: 3 to 5g daily. No loading phase needed. Mix into morning water or a shake.
- Collagen peptides: 10g daily. Mix into coffee, water, or a smoothie. A 2021 review found hydrolyzed collagen supplementation supported skin hydration, elasticity, and density across multiple controlled trials.4
- Ashwagandha (KSM-66): 300 to 600mg daily in the evening. A 2025 meta-analysis of 15 RCTs found ashwagandha significantly reduced measured serum cortisol (mean reduction of 2.36 units, P less than 0.0001) at 8 weeks.9 Chronic elevated cortisol directly impairs collagen synthesis and slows skin barrier recovery, so managing it is a core protocol variable, not just a general wellness recommendation.10
For the full rationale behind each supplement and the evidence on dosing, see the looksmaxxing supplements guide.
Grooming (the quick wins)
- Day 8 or 9: Book a quality haircut. Tell the barber your face shape and ask what they recommend. A good cut is a force multiplier on everything else.
- Day 10: Clean up your brows. Remove strays between and below the brow only. Do not reshape. Just neaten.
- Facial hair audit: if your beard is patchy, go clean-shaven or short stubble. If it is full, shape it to enhance your jawline.
Training
- Maintain 3 to 4 sessions per week
- Begin progressive overload: add 2.5 to 5 lbs or 1 to 2 reps per session to compound lifts
- Creatine begins supporting strength output within days of consistent daily dosing
Day 14 check-in
- Take comparison photos in the same conditions as Day 0
- Expect: reduced oil and shine, smoother texture, improved hydration, less post-shave irritation
- The haircut and grooming changes should produce a visibly different first impression already
- Training strength may be noticeably improved (creatine saturation beginning)
04Week 3: optimize and expand
Skincare
- Continue Tier 2 protocol. It should feel automatic by now.
- GHK-Cu should be daily AM and PM if your skin tolerates it well. Darker skin types (Fitzpatrick III to VI) should patch-test before going fully daily, as copper peptides can occasionally cause temporary sensitivity.
- You are now entering the window where clinical studies show measurable texture and hydration improvement. The Badenhorst 2016 RCT used an 8-week timeframe to observe the 55.8% wrinkle-volume result; you are at the halfway point.
Nutrition (get precise)
- Track calories and protein for at least 5 of 7 days this week
- Calculate maintenance calories (bodyweight in lbs, multiplied by 14 to 16). If fat loss is a goal, eat 300 to 500 below maintenance.
- Maintain 1.6 to 2.2g protein per kg even in a deficit. Protein preserves muscle during fat loss.
- One week of tracking calibrates your intuition. After it, portion sizes become instinctive.
Posture
- Daily chin tucks: 3 sets of 10, hold each 5 seconds. Corrects forward head posture.
- Wall slides: 3 sets of 10. Opens the chest and pulls shoulders back.
- Conscious checks throughout the day: ears over shoulders, shoulders over hips.
- Posture correction is immediately visible in profile. The jawline looks more defined, the neck looks longer, overall presence improves.
Mewing (introduction)
- Begin practicing proper tongue posture: full tongue flat against the roof of the mouth, lips sealed, teeth lightly touching.
- Maintain this during non-speaking hours. It will feel unnatural initially.
- Do not expect visible jaw changes in 30 days. Mewing is a long-game intervention, and current peer-reviewed evidence on bone remodeling in adults is limited to observational data, with no randomized controlled trials confirming structural change. The documented near-term benefit is reduced mouth breathing and improved resting facial posture.
- Full technique and evidence review in the mewing guide.
Style audit
- Pull out every piece of clothing you wear regularly. Try each on.
- Does it fit? Shoulders at the seam, body follows your shape, sleeves at mid-bicep (short) or wrist (long).
- Remove anything too big, too worn, or poorly fitting. Donate it.
- Identify 2 to 3 gaps: a well-fitting dark t-shirt, properly tapered jeans or chinos, clean white sneakers or minimalist boots. Budget $100 to $200 for essentials.
Day 21 check-in
- Skincare routine should be fully habitual, zero willpower required
- 10 or more training sessions completed across 3 weeks
- Grooming should look maintained
- Calorie and protein data from at least 5 days
- Posture noticeably more natural when you remember to check it
05Week 4: refine and measure
Skincare
- Continue full Tier 2 protocol. By Day 22, you have been on niacinamide for 3 weeks and GHK-Cu for 2 weeks consistently.
- Oily skin types tend to see faster and more dramatic niacinamide results than dry or sensitive skin, because sebum regulation is the primary mechanism.2 Dry and sensitive skin types see the biggest benefits from GHK-Cu's barrier-supporting and anti-inflammatory properties. Both see meaningful texture improvement.
- For Tier 3 in Month 2 (adding retinol and vitamin C), the full looksmaxxing skincare protocol covers the evidence and layering sequence.
Training
- 12 to 16 sessions completed. Progressive overload should be visible: more weight, more reps, or both versus Week 1.
- If body composition change is a primary goal, ensure caloric deficit is consistent. Visible face changes from fat loss typically appear around weeks 4 to 6.
- Creatine is fully saturated by now after 2 to 3 weeks of daily dosing. You may notice increased muscle fullness and training capacity.
Day 30: the final check-in
- Take Day 30 photos. Same conditions as Day 0 and Day 14. Three angles, after cleansing, natural light.
- Compare Day 0 and Day 30 side by side. Changes in skin texture, tone, hydration, oil levels, grooming, posture, and overall presentation.
- Write down what you notice. Improvements are consistently more visible in photos than in the mirror because you adapt to daily incremental change.
- Note which habits required effort and which became automatic. This tells you where to focus in Month 2.
What you should see at Day 30
- Skin: Measurably smoother texture, reduced oiliness, improved hydration, less post-cleanse irritation, early signs of firmer appearance. Clinical data aligns these outcomes with the 4-week mark for both niacinamide and GHK-Cu.
- Body: Increased training strength from creatine effect, improved energy, potentially 2 to 4 lbs of muscle with consistent training and protein. Visible body composition change depends on starting point and deficit adherence.
- Grooming: A maintained, intentional appearance. Haircut, brows, and facial hair all dialed in. This alone creates a noticeably different first impression.
- Habits: A sustainable daily system running on autopilot. This is the actual outcome of the 30-day challenge. The habits produce compounding results over months.
Day 30 is not a finish line. It is the end of the installation period for a system you run indefinitely. The most dramatic transformation happens between Day 30 and Day 90, as skincare actives, body composition changes, and habit consistency compound simultaneously.
06Copper peptide serums compared
The copper peptide serum market spans an enormous price range with very different formulation approaches. Here is an anonymized breakdown of the main tiers, from budget to prestige, with the real specs that matter for a 30-day glow up protocol. MAXXING Glow is the named and highlighted row.
| Product tier | GHK-Cu | Other peptides | Price per mL | Niacinamide compatible | Routine position |
|---|---|---|---|---|---|
| Budget single-active formula (0.10% GHK-Cu, 1.5% HA) | 0.10% | None | ~$0.73 | Yes | Serum, water-based |
| MAXXING Glow GHK-Cu Serum MAXXING | 0.2% | None (single active) | See site | Yes | Serum, water-based |
| Budget multi-peptide + HA complex (1% total peptide blend) | Part of 1% blend | 5 additional peptides, HA cross-polymer | ~$1.07 | Yes | Serum, water-based |
| Mid-tier multi-copper complex (1% GHK-Cu + 1% free GHK + repair peptides) | 1% | Tripeptide-29, repair peptides, HA | ~$2.07 | Yes | Serum, water-based |
| Prestige squalane-copper oil-serum hybrid (GHK-Cu + Copper PCA blend) | Undisclosed blend | Paracress extract, ectoin, 2 peptides, PGA, squalane | ~$1.38 | Yes | Oil-serum, use before/after moisturizer |
| Prestige dual-copper + ectoin repair serum (2% copper lysinate + 1% GHK-Cu complex) | 1% complex | 2% copper lysinate, acetyl hexapeptide, ectoin, ergothioneine | ~$6.63 | Yes | Serum, water-based |
The practical point here is not that higher concentration is always better. GHK-Cu is a signaling peptide that is active at nanomolar concentrations: a 1988 in vitro study demonstrated maximum collagen stimulation at 10 to the power of negative 9 molar.5 In cosmetic formulation, stability, vehicle chemistry, and delivery matter at least as much as raw percentage. The case for a single-active serum is transparency: you know exactly what you are applying and at what level, and you can attribute results cleanly.
07Niacinamide serums compared
Niacinamide is the Week 1 anchor of this protocol. These are the main tiers available, anonymized, with the specs that matter for glow-up purposes.
| Product tier | Niacinamide % | Key co-ingredients | Price per mL | Skin type focus |
|---|---|---|---|---|
| Budget drugstore 10% + Zinc 1% | 10% | Zinc PCA 1% | ~$0.20 | Oily, all types |
| MAXXING Clear Dominance MAXXING | 4-5% | Ceramide-compatible, fragrance-free | See site | All types, sensitive-safe |
| Mid-range 12% + Zinc 2% with HA and vitamin E | 12% | Zinc PCA 2%, sodium hyaluronate, vitamin E, glycerin | ~$0.57 | All types |
| Mid-range 15% + Acetyl glucosamine + Zinc PCA | 15% | N-acetylglucosamine, Zinc PCA, allantoin, trehalose | ~$1.25 | Oily, acne-prone |
| Prestige minimalist 5% (10 ingredients) | 5% | Sodium hyaluronate, glycerin only | ~$1.33 | Sensitive, all types |
| Prestige 10% multi-antioxidant booster | 10% | Licorice root, ascorbyl glucoside, acetyl glucosamine, beta-glucan, CoQ10, EGCG | ~$2.45 | All types, aging-focused |
The clinical evidence on niacinamide concentration is worth stating plainly: most of the landmark RCTs used 2 to 5%, not 10% or higher. The 2006 Draelos sebum study used 2%.2 The 2005 Bissett comprehensive aging trial used 5%.3 Higher concentrations can cause flushing and irritation, particularly on sensitive or barrier-compromised skin. MAXXING Clear Dominance is intentionally formulated in the evidence-backed range so it can be used daily without reactivity concerns.
Niacinamide at 4 to 5% is not a compromise. It is the concentration range where the most rigorous human clinical data was gathered. Sensitivity skin types and darker Fitzpatrick skin types should start at this range before considering higher concentrations.
08Daily habits checklist (all 30 days)
Print this or screenshot it. Every day for 30 days, check every box.
- AM skincare: Cleanser, niacinamide, GHK-Cu (from Week 2), moisturizer, SPF
- PM skincare: Cleanser, GHK-Cu (from Week 2), moisturizer
- Protein target: 1.6 to 2.2g per kg bodyweight
- Water: 2 to 3 liters
- Training: 3 to 4 sessions per week, or active recovery on off days
- Supplements from Week 2: creatine, collagen peptides, ashwagandha
- Sleep: 7 to 9 hours, consistent bed and wake time
- Posture from Week 3: chin tuck set, conscious checks through the day
- Mewing from Week 3: tongue on roof of mouth during non-speaking hours
The compound effect of hitting these daily habits for 30 consecutive days exceeds any single product, supplement, or procedure. Consistency is the protocol. The 30-day challenge installs the habits. Months 2 through 6 are where the transformation compounds into something dramatic.
09Day 31 and beyond: making it permanent
The 30-day challenge is the installation period for a system you run indefinitely. Month 2 is where the real transformation becomes visible.
Skincare Tier 3
If you are ready, add retinol (2 to 3 nights per week) and vitamin C serum (alternating PM nights). This is the full looksmaxxing skincare protocol. The clinical results from GHK-Cu peak around the 8-week mark: the Badenhorst 2016 study recorded its 55.8% wrinkle-volume reduction figure at 8 weeks.1 You are halfway there at Day 30.
Training progression
Move from general consistency to a structured program. A 4-day upper/lower split with tracked progressive overload delivers the fastest body composition changes for intermediate trainees. Continue creatine and protein intake. The full rationale for creatine dosing and safety is covered in the looksmaxxing supplements guide.11
Nutrition precision
If fat loss is still a goal, maintain your deficit. If you have reached a lean range (12 to 15% body fat), transition to maintenance and focus on recomposition: building muscle while maintaining leanness.
Advanced grooming
Consider a barber who understands face shape optimization. Experiment with beard styling if applicable. Nail care, lip care with SPF balm, and a considered fragrance are the next grooming tier.
Track at Day 60 and Day 90
Take the same baseline photos at Day 60 and Day 90 under identical conditions. The Day 0 to Day 90 comparison will show dramatic change across multiple categories simultaneously. This is the before-and-after that validates the entire system. See the before and after tracking guide for the full photo methodology.
Skincare tier ladder
Here is how MAXXING structures the product progression across months:
| Tier | Products | When to start | Expected result timeline | MAXXING SKU |
|---|---|---|---|---|
| Tier 1 | Cleanser, niacinamide serum, ceramide moisturizer, SPF | Week 1 (Day 1) | Oil control and texture: 1 to 2 weeks. Barrier improvement: 2 to 4 weeks. | Fresh Start, Clear Dominance, Damage Control |
| Tier 2 Challenge core | Tier 1 + GHK-Cu copper peptide serum | Week 2 (Day 8) | Texture and hydration: 3 to 4 weeks. Firming and collagen support: 6 to 8 weeks. | MAXXING Glow |
| Tier 3 | Tier 2 + retinol (PM, alternating nights) + vitamin C (AM) | Month 2 (Day 31+) | Fine-line reduction: 8 to 12 weeks. Hyperpigmentation: 10 to 16 weeks. | Coming soon to GlowMaxxing |
For the full science behind each active in the tier system, the GHK-Cu complete guide and the skincare routine guide cover every mechanism in clinical depth. The softmaxxing vs hardmaxxing guide covers how the skincare and supplement protocol fits into the broader looksmaxxing framework.
10FAQ
Yes, with important context. In 30 days you will see measurable skin improvement from niacinamide (oil control, texture, hydration), initial training adaptations, and immediate grooming upgrades. You will not see the full depth of results that take 8 to 12 weeks, such as the 55.8% wrinkle-volume reduction in the Badenhorst GHK-Cu trial or significant body composition change. The 30-day challenge installs the habits and protocols that produce dramatic transformation over 3 to 6 months of continued use.
The fastest visible improvements come from grooming (haircut and brow cleanup, immediate), style (well-fitting clothes, immediate), and skincare (niacinamide reduces oil and supports smoother texture within 1 to 2 weeks). These three can produce a noticeably different first impression within 7 to 14 days. Deeper structural changes, including body composition and collagen-density improvement, take 4 to 12 weeks but produce more dramatic and lasting results.
Minimum investment: $50 to $100 for core skincare (cleanser, niacinamide, moisturizer, SPF) plus $0 to $50 for gym access. Adding GHK-Cu serum in Week 2 adds $30 to $50. Supplements (collagen, creatine, ashwagandha) add $55 to $80. Grooming (haircut, brow cleanup) adds $30 to $50. Total range: $80 to $280 for the full 30-day challenge. Many high-impact interventions such as sleep, water, posture, and bodyweight training are free.
Resistance training is strongly recommended but a gym is not required. Bodyweight exercises (push-ups, pull-ups, squats, lunges, planks) provide sufficient stimulus for beginners for the first 30 to 60 days. The key is progressive overload: making the exercises harder over time. A gym with free weights accelerates results significantly. Lower body fat combined with more muscle is the single highest-leverage physical change for facial aesthetics.
Do not restart. Pick up exactly where you left off. Missing one day of skincare or training does not reset your progress. The collagen your fibroblasts are building does not disappear overnight. What matters is the overall consistency ratio: hitting 26 out of 30 days (87%) produces excellent results. What kills progress is using one missed day as an excuse to quit entirely. Skip the guilt and resume the protocol.
Realistically at Day 30: smoother, less oily skin with improved texture and hydration. Maintained grooming (haircut, brows, facial hair). Initial strength gains from training. Better sleep quality and energy levels. A complete daily system running on autopilot. Visible change in Day 0 versus Day 30 comparison photos. The most dramatic transformation happens between Day 30 and Day 90 as skincare actives and body composition changes compound.
They work on different timelines and serve different purposes, which is why the MAXXING protocol layers them sequentially. Niacinamide is faster acting: it supports oil control and texture improvement in 1 to 2 weeks. GHK-Cu works at a deeper structural level, supporting the appearance of firmer, more collagen-dense skin over 4 to 8 weeks. Starting with niacinamide in Week 1 lets you establish the habit and see early results. Adding MAXXING Glow GHK-Cu in Week 2 extends the protocol into longer-arc transformation. See the full GHK-Cu guide for the clinical evidence comparison.
Significantly. Chronic stress activates the HPA axis, producing sustained elevated cortisol, which directly suppresses collagen synthesis in dermal fibroblasts and slows barrier recovery. A 2024 study found that moderate-stress individuals had 33% more fine lines and 73% slower fibroblast wound healing compared to low-stress controls.10 This is why ashwagandha is part of the Week 2 supplement stack: a 2025 meta-analysis found it significantly reduces serum cortisol at 8 weeks.9 Managing cortisol is not optional during this challenge. It directly determines how well your skin responds to the actives you apply.
Follow a four-pillar protocol: skincare (cleanser, niacinamide, moisturizer, SPF daily from Day 1, GHK-Cu serum added Week 2), resistance training (3 to 4 sessions per week), nutrition (high protein, low processed sugar, 3L water daily), and grooming (haircut and brow cleanup in Week 1). Stack sleep at 7 to 9 hours and manage stress. Consistency across all four pillars is what separates visible results from no results.
You can start a transformation, but 30 days is the beginning, not the finish line. In one month of consistent resistance training and high-protein eating, most people notice initial strength gains, slightly improved muscle definition, and a modest drop in water retention. Significant body composition change (meaningful fat loss or visible muscle gain) takes 8 to 16 weeks. The 30-day challenge builds the habits and baseline that make those longer-arc results possible.
// References
- Badenhorst T, et al. "Effects of GHK-Cu on MMP and TIMP Expression, Collagen and Elastin Production, and Facial Wrinkle Parameters." J Aging Sci. 2016;4(3):166. Randomized double-blind split-face RCT, 40 subjects, 8 weeks.
- Draelos ZD, et al. "The effect of 2% niacinamide on facial sebum production." J Cosmet Laser Ther. 2006;8(2):96-101. PubMed
- Bissett DL, et al. "Niacinamide: A B vitamin that improves aging facial skin appearance." Dermatol Surg. 2005;31(7 Pt 2):860-865. PubMed
- de Miranda RB, et al. "Effects of hydrolyzed collagen supplementation on skin aging." Int J Dermatol. 2021;60(12):1449-1461. PubMed
- Maquart FX, et al. "Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+." FEBS Lett. 1988;238(2):343-346. PubMed
- Oyetakin-White P, et al. "Does poor sleep quality affect skin ageing?" Clin Exp Dermatol. 2015;40(1):17-22. PubMed
- Sundelin T, et al. "Cues of fatigue: effects of sleep deprivation on facial appearance." Sleep. 2013;36(9):1355-1360. PubMed
- Sundelin T, et al. "Negative effects of restricted sleep on facial appearance and social appeal." R Soc Open Sci. 2017;4(5):160918. PMC
- Pratte MA, et al. (meta-analysis lead). "Effects of Ashwagandha Supplements on Cortisol, Stress, and Anxiety Levels in Adults: A Systematic Review and Meta-Analysis." BJPsych Open. 2025. doi:10.1192/bjo.2025.10136. 15 RCTs, n=873. PMC
- Pujos M, et al. "Impact of Chronic Moderate Psychological Stress on Skin Aging." J Cosmet Dermatol. 2024. doi:10.1111/jocd.16634. PubMed
- Kreider RB, et al. "International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine." JISSN. 2017;14:18. PubMed
