Head to head

CJC-1295 with DAC vs MK-677

GH secretagogue

Side-by-side on recovery and sleep, dosing, kinetics and evidence — with an honest verdict at the end.

Verdict

Route decides this one, not potency

On overlap and evidence these are close enough that the data cannot pick a winner. What it can tell you is that CJC-1295 with DAC means a needle and a reconstitution step and MK-677 does not. For most people that, plus whether they will actually keep to once a week dosing, is what really decides it.

What you are actually choosing between

Both are classed here as growth hormone secretagogues, so this is a within-class choice: the mechanism is broadly shared and what separates them is kinetics, route, and how much has actually been tested.

The overlap is recovery and sleep and muscle growth. On this site's goal weighting — an editorial priority score, not a measure of effect size — CJC-1295 with DAC rates 3/5 for recovery and sleep and MK-677 rates 5/5. Outside that overlap only MK-677 goes further, carrying weight for appetite control; CJC-1295 with DAC's declared goals stop at the overlap.

The evidence

MK-677 sits one step firmer: controlled human trials behind it, without an approval — never approved, and trials flagged higher fasting glucose. CJC-1295 with DAC has some human data, but it is small, old, or uncontrolled — phase 1 single-dose studies only; development was discontinued. One tier is a real difference but not a decisive one; it should not on its own settle the choice.

How they differ in practice

CJC-1295 with DAC is a subcutaneous injection; MK-677 is taken by mouth. That is the difference most people actually feel: CJC-1295 with DAC means reconstituting a vial and injecting; MK-677 does not require either. If needles are the deciding factor, this line settles it before any of the rest matters.

Kinetics are not close. CJC-1295 with DAC has a half-life of 7 days against MK-677's 24 h — roughly 7× — which is why one is dosed once a week and the other once daily. A long half-life means a steadier level and a mistake you cannot take back for days; a short one means timing matters and a bad day washes out fast.

Committed time differs: CJC-1295 with DAC runs 12 weeks, MK-677 runs 16 weeks.

Source notes

What the evidence actually says

Verbatim, so you can check the verdict above against what it was built from.

CJC-1295 with DAC

Dosed once weekly at 1 to 2 mg, which is how it is overwhelmingly run in practice: the albumin binding makes the weekly total the meaningful quantity, and splitting it across the week buys nothing. A GHRH (1-29) analogue carrying a Drug Affinity Complex maleimide that binds serum albumin, which is the ONLY reason it differs from the no-DAC version: the terminal half-life runs roughly 6 to 8 days instead of minutes, so a single dose produces a sustained rise in GH and IGF-1 rather than a discrete pulse. Phase 1 human dosing studies used single subcutaneous doses of about 30 to 250 mcg/kg. Development was discontinued and it is NOT approved by any regulator; consumer supply is research-chemical grade. Because exposure is continuous rather than pulsatile, it is the less physiologic of the two CJC-1295 forms and carries more of the water-retention and glucose signal.

MK-677 (Ibutamoren)

Orally active, long-acting ghrelin receptor (GHS-R1a) agonist that raises GH and IGF-1 for around 24 hours per dose. It has been through multiple human trials, including a two-year study in older adults, but was never approved for any indication and trials also flagged increased fasting glucose and reduced insulin sensitivity. It is a non-peptide small molecule, so it is taken by mouth rather than injected.

Side by side

The numbers

CJC-1295 with DAC compared with MK-677
Attribute	CJC-1295 with DAC	MK-677
Class	GH secretagogue	GH secretagogue
Routes	Subcutaneous	Oral
Dose range	1 mg–2 mg (typical 1.5 mg)	10 mg–25 mg (typical 15 mg)
Frequency	Once a week	Once daily
Half-life	7 days	24 h
Cycle length	12 weeks	16 weeks
Experience	Intermediate	Intermediate
Evidence	Limited human data	Controlled human trials
Contraindications	Pregnant / nursing Active malignancy Under 18	Pregnant / nursing Active malignancy Under 18
Side effects	Water retention and puffiness, more pronounced than with short-acting GHRHs Injection site redness or swelling Head rush, flushing or transient dizziness Tingling or numbness in the hands, which can reflect carpal tunnel pressure Reduced insulin sensitivity and higher fasting glucose with sustained elevation Lethargy or headache, often reported in the first week	Pronounced increase in appetite, often within the first few days Water retention, puffiness in the face and ankles, and rapid scale weight gain Raised fasting blood glucose and reduced insulin sensitivity — a real concern for anyone prediabetic or diabetic, and worth monitoring with bloodwork on longer runs Lethargy or grogginess the morning after a pre-bed dose Numbness or tingling in the hands, sometimes carpal-tunnel-like Vivid dreams and deeper but occasionally disrupted sleep Mild joint aches at higher doses

Turn a typical dose into a mark on the syringe: CJC-1295 with DAC

Goals

Where they overlap, and where they do not

Goal	CJC-1295 with DAC	MK-677
recovery and sleep	CJC-1295 with DAC: 3/5	MK-677: 5/5
muscle growth	CJC-1295 with DAC: 4/5	MK-677: 4/5
injury repair	CJC-1295 with DAC: 3/5	MK-677: 2/5
longevity	CJC-1295 with DAC: 2/5	MK-677: 2/5
appetite controlone only	CJC-1295 with DAC: —	MK-677: 5/5
fat lossone only	CJC-1295 with DAC: 2/5	MK-677: —
skin and hairone only	CJC-1295 with DAC: —	MK-677: 2/5

They overlap on 4 goals and diverge on 3. Weights are this site’s editorial priority score out of 5 — how central a goal is to why people use a compound. They are not effect sizes and two 5s do not mean two equal results.

Go deeper

MonographCJC-1295 with DACMechanism, protocol, storage, sources.MonographMK-677 (Ibutamoren)Mechanism, protocol, storage, sources.ToolReconstitution calculatorTurn either dose above into a mark on the syringe.

Other comparisons with these two

Educational information only, not medical advice. Talk to a licensed clinician before starting, changing, or stopping anything.