Chapter 5 — Supporting axis: circadian, cortisol, and growth hormone timing

NAD+ runs on a clock. So does your repair.

You can flood the cell with NMN, MOTS-c, and 5-Amino-1MQ, and still get a mediocre response — because NAD+ availability is gated by the circadian loop, not just the supply chain. The mitochondria you're trying to fix don't operate on a flat 24-hour line. They oscillate. Repair happens on a schedule. If your cortisol curve is inverted, your GH pulse is flat, or your sleep architecture is shallow, the substrate you're paying for is being burned by a clock that's running backwards.

This chapter wires NAD+ optimization into the three axes that actually decide whether the substrate gets used: the circadian clock itself, the cortisol curve, and the nighttime GH pulse.

What's actually happening at the cellular level

The molecular clock — BMAL1 and CLOCK as the daytime activators, PER and CRY as the nighttime repressors — is not a metaphor for "sleep schedule." It's a transcription complex that drives the rhythmic expression of NAMPT, the rate-limiting enzyme in the NAD+ salvage pathway. BMAL1/CLOCK turn NAMPT on; NAMPT makes NAD+; NAD+ activates SIRT1; SIRT1 deacetylates BMAL1 and modulates the next cycle. It's a closed loop, and it runs both ways: the production of NAD+ is controlled by the circadian cycle, while the availability of NAD+ drives the circadian cycle. Break the rhythm and you suppress NAMPT. Suppress NAMPT and you cap how much NAD+ the cell can synthesize regardless of what you're injecting.

Cortisol is the morning ignition for this whole system. The cortisol awakening response — the 30-50% spike within 30 minutes of waking — mobilizes glucose, primes norepinephrine, and signals "daytime catabolic phase." It is supposed to peak in the early morning and decline through the day to a trough at night, when anabolic GH-driven repair takes over. In chronic metabolic dysfunction, this curve flattens or inverts: low morning cortisol (sluggish ignition), high evening cortisol (suppressed nighttime repair). When the practitioner corpus describes "metabolic deafness" — cells that no longer listen to insulin — the upstream lesion is often a broken cortisol rhythm preventing the night-time anabolic window from ever opening.

DSIP (Delta Sleep-Inducing Peptide) is the leverage point on the cortisol axis. The substrate describes DSIP as the program that makes the suprachiasmatic nucleus reorganize its outputs — not a sedative, but a rhythm restorer. By re-establishing the cortisol peak-and-trough pattern, DSIP removes the chronic catabolic signal that suppresses insulin signaling and blocks the nighttime repair window. Cells start listening to insulin again, glucose disposal improves, and the GH pulse has somewhere to land.

The GH pulse itself is the third lever. Endogenous GH releases in pulsatile bursts during slow-wave sleep, peaking 1-2 hours after sleep onset. SIRT1 activity (NAD+-dependent) is highest during this same window. Stack GH-secretagogue dosing with the natural pulse and you get a multiplicative effect on mitochondrial biogenesis, IGF-1-driven repair, and slow-wave-sleep depth. CJC-1295 provides the GHRH baseline; Ipamorelin hits the GHSR1A receptor for the pulsatile spike. The two pathways are complementary, not redundant — combined output exceeds either compound alone.

One critical gate: if fasting insulin is above 8 mIU/L, GH secretagogues will worsen insulin resistance because growth hormone naturally antagonizes insulin. The substrate is explicit — fix insulin resistance first, then layer GH secretagogues. This is why Chapter 3's metabolic reset comes before this chapter's GH stack.

Protocol — the supporting axis stack

Timing rules from the substrate:

• Dose Ipamorelin 2+ hours after the last meal — elevated insulin blunts GH release.
• Separate GH secretagogue dosing from progesterone cream by 4-6 hours — progesterone blunts GH secretagogue effect at concurrent dosing.
• Take DSIP and Ipamorelin in the same nighttime window, but stagger by 15-30 minutes — DSIP first to set the sleep program, Ipamorelin second to ride the pulse.
• Do not stack a supraphysiologic melatonin dose with bright light — the corpus describes this as "pressing gas and brake at the same time." Dark room or red/orange blue-blocking glasses 3-4 hours before bed.

What you should feel

• Nights 1-3 — Sleep onset faster, deeper. DSIP effects show up immediately for most users.
• Week 1 — Morning wakefulness without an alarm starts to return. Cortisol awakening response normalizing.
• Week 2 — Measurable deepening of delta-wave architecture if you're tracking with a sleep ring or EEG headband. Recovery scores climb.
• Week 3-4 — Body composition shift becomes visible. Skin quality improves (GH/IGF-1 effect on collagen). Morning fasting glucose trends down as insulin signaling recovers.
• Week 4-6 — IGF-1 measurable on bloodwork. Fasting insulin should be tracked — it should stay flat or drop, not climb.
• Week 6-8 — Sustained energy curve through the afternoon without the 2-3pm crash. The "metabolic deafness" pattern starts breaking.

What's NOT happening yet

• You are not building muscle from the GH stack alone. CJC/Ipamorelin restores a physiologic GH pulse — it doesn't deliver supraphysiologic IGF-1 the way exogenous GH does. Muscle response is real but slow.
• You are not "fixing" sleep with DSIP if your light hygiene is broken. DSIP restores rhythm; it can't override 11pm phone screens and overhead LEDs.
• High-dose melatonin is not a sleep aid at supraphysiologic doses — the corpus describes it as a mitochondrial antioxidant. Drowsiness blunts at high doses; some users dose it in late afternoon for that reason.
• IGF-1 climbing is not automatically protective. If fasting insulin is elevated, rising IGF-1 against a backdrop of insulin resistance is a worse metabolic profile, not a better one. Pull bloodwork.
• The morning cortisol normalization is not linear. Expect a 1-2 week window where you may feel flatter as the curve re-establishes. Push through.

The corpus describes a clock — restore the rhythm, and the substrate works. Track it. Adjust.