Onset: ~3-4 hours post-dose for the cognitive readout to fully emerge (matches Gordji-Nejad 31P-MRS peak). No acute "kick" — this is not a stimulant. If Dylan takes it expecting a modafinil-style alertness boost, he'll be disappointed.

Felt effect during the sleep-deprived window:

• Reduced perceived effort on cognitive tasks — work feels less metabolically expensive
• Better held-line on working memory under fatigue (less of the "what was I just thinking?" drift)
• Subjective reaction time and processing speed feel preserved closer to rested baseline
• No euphoria, no tactile/visual changes, no mood lift beyond "less drained"
• Best described as "metabolic insurance" or "the cognitive equivalent of a slow-release IV drip" — keeps the brain off the floor when sleep loss should have it there

GI considerations at 20 g single dose:

• Bloating mild-to-moderate for first 1-2 hours
• Occasional loose stool / diarrhea (~10-15% of users)
• Resolves within 4-6 hours
• Mitigation: dissolve in 250-500 mL hot water (improves solubility), split into 2× 10 g doses 30-45 min apart, take with food (light protein + complex carb works well)

Duration of cognitive benefit: ~6-12 hours per Gordji-Nejad time-course; the brain creatine pool stays elevated for 12-24 hours before declining. A single dose covers one sleep-deprived window; doesn't compound across multiple consecutive days unless re-dosed.

Synergistic with (during the sleep-deprived cognitive window)

• Caffeine 100-200 mg — additive on subjective alertness; mechanism orthogonal (caffeine = adenosine antagonism; creatine = ATP buffering). Stack-safe per modern interpretation of the old Vandenberghe 1996 caveat.
• L-theanine 200 mg — smooths the caffeine adrenergic edge without blunting alertness. Dylan already runs theanine in V4.
• Modafinil 100-200 mg — Dylan's primary V5 wake-promoter. No documented interaction with creatine; mechanistically independent (modafinil = histamine/orexin/dopamine wakefulness; creatine = ATP buffering). Likely complementary for sustained sleep-deprived cognitive load — modafinil keeps you awake and alert; creatine keeps the metabolic substrate pool from collapsing.
• L-tyrosine 1-2 g — supports catecholamine synthesis under cognitive load. Stack-safe.
• Magnesium L-threonate (V4 magtein) — supports synaptic plasticity; theoretical complement to brain creatine for cognitive demand windows. Daily basis already covered.
• ALCAR 500-1000 mg — mitochondrial fatty acid oxidation; complements creatine's ATP buffering via different pathway. Dylan's V5 plan includes ALCAR.

Avoid stacking with

• Agmatine in same dose — creatine may impair agmatine absorption per encyclopedia note. Take separately by 2-3 hr if both are in protocol. Trivial to manage.
• Nephrotoxic agents at high dose (NSAIDs at gram doses, aminoglycosides) — not absolute contraindication but caution warranted if renal stress is concurrent. Not relevant for Dylan.
• Excessive sodium bicarbonate — would alkalinize urine and affect creatine clearance. Marginal concern.

Neutral / safe co-administration

• All Dylan's V4 stack components: NAC, citicoline, magnesium glycinate + threonate, DHA, PS, curcumin, rhodiola, glycine, D3+K2, beta-alanine, vitamin C
• All V5 planned: bromantane, Adamax/Semax, apigenin, taurine, astaxanthin, l-tryptophan, Cerebrolysin cycles
• All electrolytes, whey/casein/EAAs, baseline 5-10 g/day creatine maintenance

• CYP enzymes: Creatine is not CYP-metabolized and does not induce/inhibit CYP. No interaction with modafinil, bupropion, or other CYP-metabolized stack members.
• Caffeine: No meaningful interaction. The old Vandenberghe 1996 caffeine-blunts-creatine-loading signal didn't replicate consistently and wasn't tested at acute high dose. For Gordji-Nejad-style PRN use, caffeine is fully stack-safe and likely additive.
• Diuretics: Theoretical (cellular hydration changes); no documented clinical issue.
• Modafinil + creatine: No interaction; mechanistically independent; likely complementary as discussed above.
• NSAIDs / acetaminophen at typical doses: No interaction.
• Alcohol: No documented interaction with creatine itself; alcohol obviously worsens the sleep-deprived cognitive baseline the protocol is meant to rescue, so semi-incompatible at the use-case level.

• SLC6A8 (CRT, creatine transporter): Rare X-linked deficiency (~1% of X-linked intellectual disability) requires creatine precursors instead of oral creatine. Healthy population variants haven't been well-studied for high-dose acute response; theoretically lower-activity variants might still respond to mass-action loading at 20 g (the acute dose pushes by concentration gradient even with reduced transport efficiency).
• GAMT / AGAT: Affect endogenous synthesis. Severe deficiencies clinically obvious; subclinical variation theoretical.
• MTHFR variants: Affect methylation capacity. Since endogenous creatine synthesis is methyl-intensive, MTHFR-variant carriers benefit more from creatine supplementation generally (less SAM consumed for creatine synthesis). Plausible mechanism, limited direct PGx-creatine-RCT data.
• Vegetarian status (non-genetic but functionally similar): Vegetarians have lower baseline brain creatine and respond strongly to lower doses; the Gordji-Nejad acute protocol may produce even larger effects in vegetarians (untested). Not Dylan (carnivore).
• 23andMe relevance for Dylan (results June 2026): Check SLC6A8, MTHFR, GAMT/AGAT for completeness. Likely no actionable change to the 20 g acute protocol; high-dose mass action minimizes transporter-variant sensitivity.

Bottom line: Dylan's existing creatine monohydrate supply works perfectly. No new sourcing needed. Cost per acute use is trivial (~$0.30-0.50). Frequency cap (1-3×/month) means the cost overhead is negligible against the cognitive benefit on high-leverage days.

Practical kit:

• Existing creatine monohydrate jar
• A 30 g (~6 teaspoon) measuring scoop or kitchen scale for accurate dose
• A 500 mL mug + electric kettle (for hot-water dissolution per Gordji-Nejad spec)
• Time the dose 3-4 hr before the predicted cognitive window

• Pre-protocol baseline (already met for Dylan via baseline creatine use):
  • Body weight (expect 0.5-1 kg same-day water blip on acute dose; not chronic gain since acute use is intermittent)
  • Subjective cognitive performance during sleep-deprived windows (calibrate with 1-2 sleep-deprived days without the protocol vs 1-2 with the protocol; honest A/B comparison over 4-8 weeks)
  • Reaction time / working memory via apps (Cambridge Brain Sciences, Quantified Mind, simple Stroop) on protocol vs non-protocol sleep-deprived days
• During acute use:
  • Subjective alertness and processing speed during the 4-12 hr post-dose window
  • Sleep onset that night (high-dose creatine doesn't disrupt sleep mechanistically; if it does anything, it's mildly net-positive for next-night sleep architecture)
  • GI tolerability (split if needed)
• June 2026 bloodwork window: flag the lab if any acute high-dose protocol has been used within 24 hr; cystatin C-based eGFR is the cleaner marker than creatinine-based.
• Long-term: No long-term monitoring needed beyond Dylan's standard annual labs. No accumulation concern at PRN frequency.