The 2006 Teichman paper reported prolonged growth-hormone (GH) and insulin-like growth factor 1 (IGF-1) responses in two small, randomized healthy-adult studies. These findings support a pharmacokinetic and endocrine signal, not a demonstrated improvement in health, symptoms, physical performance or body composition. Adverse events were frequent, even though the abstract reported no serious adverse reactions.[1][2][3]
This review combines the accessible primary abstract and metadata with FDA’s later reconstruction of the studies. The full journal paper, original protocols and statistical analysis plans were not obtained for this review. Consequently, detailed cohort and safety findings below are attributed to the FDA review, not presented as a new full-paper audit.
Study identity and scope
| Feature | Source-specific description |
|---|---|
| Publication | Teichman et al., Journal of Clinical Endocrinology & Metabolism 91(3):799–805; PMID 16352683; DOI 10.1210/jc.2005-1536 |
| Population | Healthy adults aged 21–61 years at two investigational sites |
| Design | Two randomized, double-blind, placebo-controlled ascending-exposure studies |
| Observation | A 28-day single-exposure study and a 49-day repeat-exposure study |
| Main measurements described in the abstract | GH and IGF-1 peak concentrations and areas under the concentration-time curve; CJC-1295 pharmacokinetics |
| Material | CJC-1295 DAC active moiety, with the exact salt/form unspecified in FDA’s reconstruction |
The studies used controlled research exposures. This page does not reproduce an administration schedule or translate those exposures into practical-use guidance.
How the study counts fit together
FDA’s cohort account includes an additional group in Study 1 that is easily missed.[3]
| Protocol | Cohort construction in FDA’s review | Study enrollments |
|---|---|---|
| Study 1 | Four initial six-person cohorts, each with five active and one placebo participant, plus an additional 18-person cohort with 15 active and three placebo participants at an already studied exposure level | 35 active and seven placebo; 42 total |
| Study 2 | Four six-person cohorts, each with five active and one placebo participant | 20 active and four placebo; 24 total |
There were four initial exposure levels in Study 1, not just four equal-sized cohorts containing all 42 enrollments. Together, the two protocols account for 66 study enrollments. The accessible accounts do not establish that these were 66 distinct people or supply a complete participant-flow and outcome-specific analysis-denominator account.
These enrollment numbers must not be treated automatically as the number contributing to every blood-sampling analysis. Nor does the available account verify complete follow-up, an intention-to-treat analysis, a per-protocol population or a missing-data rule.
What the hormone and exposure measurements mean
Pharmacokinetics describes the measured concentration of the study substance over time. Pharmacodynamics describes its biological effects, here mainly changes in the GH–IGF-1 axis. A peak concentration and an area under the concentration-time curve answer different questions: how high a measured level reached versus its integrated pattern over a specified interval.
The abstract reports that after a single exposure, mean GH increased approximately 2- to 10-fold for at least six days, while mean IGF-1 increased approximately 1.5- to 3-fold for 9–11 days. The estimated CJC-1295 half-life was 5.8–8.1 days.[1][2] That half-life range is not a confidence interval for clinical benefit, and neither persistence nor a larger hormone response establishes a better health outcome.
These biomarker findings require the distinctions explained in surrogate endpoints and clinical outcomes. They do not directly measure how a person feels or functions, and this reviewed evidence does not establish a validated surrogate relationship for claims about muscle, recovery, sleep or longevity.
Baseline and placebo are different comparisons
The FDA reconstruction separates comparisons that should not be collapsed into a generic statement that “both hormones improved versus placebo.”[3]
| Result account | Comparison reported | Interpretation limit |
|---|---|---|
| Study 1 GH area under the curve over days 0–7 | Significant increases versus placebo at the three higher exposure levels | An endocrine comparison in small study groups, not a patient-benefit effect |
| Study 1 IGF-1 area under the curve over days 0–7 | Significant increases versus baseline at the three higher exposure levels | A within-group baseline comparison is not the same statistical test as an active–placebo contrast |
| Study 2 IGF-1 exposure summaries | Selected active–placebo and active-group comparisons over specified intervals | These belong to the repeat-exposure protocol and do not change the comparator used for Study 1 |
FDA describes placebo IGF-1 levels as stable in Study 1. That observation does not turn the reported baseline tests into verified placebo-controlled tests. FDA also reports that IGF-1 exceeded age- and sex-adjusted normal ranges in the highest Study 1 group; exceeding a reference range is not evidence of added benefit.
The abstract’s fold-change wording and FDA’s later IGF-1 fold wording are not identical. The numerical summary above follows the primary abstract. Without the full paper and analysis materials, this review does not harmonize those wordings, certify an original endpoint hierarchy or claim that the full set of comparisons controlled multiplicity. Confidence intervals, P values and multiplicity explains why a selected significant test cannot answer all of those questions.
Repeated exposure and accumulation
The abstract reports that mean IGF-1 remained above baseline for up to 28 days after repeated study exposures. FDA describes higher CJC-1295 peak concentrations and exposure summaries after later administrations, consistent with accumulation.[1][3]
These observations do not show that repeated exposure is more beneficial or that a persistent biomarker effect is a durable clinical effect. FDA’s repeated-exposure pharmacokinetic account also involves sampling subsets and individual variability; it should not be merged into one universal half-life estimate for every participant and schedule.
The dose-response and exposure-response guide helps distinguish an exposure pattern from proof of a causal, patient-important benefit.
Adverse events and the limits of the safety claim
The abstract’s report of no serious adverse reactions does not mean there were no adverse events. FDA reports events in 33 of 35 active participants and two of seven placebo participants in Study 1. About 70% of active participants had injection-site irritation, redness, induration, pain or itching. Headache was reported in 63% of active participants versus 14% on placebo; diarrhea was reported in 43% of active participants and not in placebo participants. Transient local urticaria and vasodilatory symptoms, including flushing, warmth and transient hypotension, were also described.[3]
Those categories overlap. They cannot be added to estimate the number of affected people, and rounded percentages should not be converted into invented exact counts.
In Study 2, all active participants had an injection-site reaction, while three of four placebo participants had mild redness. “Any injection-site reaction” and “mild redness” are not identical outcome categories, so these statements do not support a like-for-like 100% versus 75% risk comparison. Other reported observations included headache, flushing, gastrointestinal symptoms, transient dizziness or hypotension, and one report of involuntary leg contractions with some loss of coordination.[3]
FDA recounts no consistent changes in the reported blood, urine, glucose, liver-function or electrocardiographic assessments. It also describes no significant antibody formation, but says assay sensitivity and validation were not described and long-term repeated-exposure data were unavailable. These findings do not exclude immunogenicity or uncommon, delayed and population-specific harms.
The DAC and salt/form boundary
FDA distinguishes CJC-1295-related substances with and without the DAC modification. Its reconstruction indicates that the human reports concerned the DAC active moiety, but did not specify a salt. This is not proof that the administered material was salt-free or that it was a particular acetate or TFA preparation.[3]
The DAC modification permits albumin bioconjugation and changes the molecular construct. FDA cautions against transferring its pharmacological profile to CJC-1295 without DAC. The extent to which DAC, rather than other sequence modifications, accounts for the prolonged profile is a separate mechanistic question; naming the modification does not resolve every mechanism.
Neither this paper nor FDA’s reconstruction authenticates the sequence, concentration, impurity profile, stability, sterility or equivalence of another material. Similar labeling is not analytical or clinical equivalence.
Commercial involvement and source transparency
FDA identifies ConjuChem as the study-material manufacturer. The publisher lists three coauthors with ConjuChem affiliations.[1][3] These are relevant disclosures, not an automatic reason to dismiss the measurements.
The accessible publisher material does not expose a complete funding and conflict-of-interest statement. This review therefore does not certify the full funding arrangements, sponsor noninvolvement or data-access agreements. It also did not obtain an original registration record, protocol history or analysis plan, and did not conduct an exhaustive registration or correction/retraction search.
The direct PubMed page encountered an access challenge during this review. Official indexed abstract text remained available, while the publisher exposed its abstract and metadata. Those access levels are different from a complete current notice audit or full-paper review.
What the dated FDA document does, and does not, establish
The cited FDA briefing contains a November 15, 2024 memorandum prepared for the December 4, 2024 Pharmacy Compounding Advisory Committee meeting. It proposed against including the evaluated CJC-1295-related substances on the 503A Bulks List, citing characterization, safety and effectiveness limitations.[3]
That advisory document is not a final rule, a product approval or a fresh September 2026 determination of legal status. Its assessment for growth-hormone deficiency also does not turn healthy-adult hormone responses into evidence of treatment benefit. Use the official-status checking guide to distinguish study evidence, advisory recommendations and approval records.
Bottom line
The evidence supports prolonged GH and IGF-1 responses to the studied DAC construct, with accumulation under repeated research exposure. It also documents frequent adverse events and unresolved analysis, long-term safety and exact-form questions. It does not establish a net clinical benefit, validate no-DAC material or authenticate another preparation.
For context, use how to read a research study and the Study Records library.
Frequently asked questions
Were there 66 participants?
FDA’s account totals 66 enrollments across two protocols: 42 in Study 1 and 24 in Study 2. The accessible evidence does not verify 66 distinct people or a common 66-person analysis population.
Did CJC-1295 raise GH and IGF-1?
The abstract reports prolonged increases in both. The comparison matters: FDA describes Study 1 GH tests versus placebo but selected IGF-1 tests versus baseline, with separate comparisons in Study 2.
Does a longer half-life mean a better clinical result?
No. Persistence describes exposure. It does not by itself show improved symptoms, function or health, and it can also matter for accumulation and safety.
Did these studies prove muscle gain, recovery or anti-aging benefit?
No such benefit is established by the reviewed outcome accounts. The accessible evidence concerns pharmacokinetic and endocrine measurements, not a demonstrated patient-important effect.
Were adverse events absent?
No. FDA’s reconstruction reports frequent events, particularly local reactions and headache. The abstract’s no-serious-adverse-reaction statement is narrower than a general safety conclusion.
Is CJC-1295 without DAC covered by these findings?
No. FDA treats the DAC modification as a material identity distinction and warns against transferring the DAC pharmacological profile to the no-DAC construct.
Does the FDA briefing approve a CJC-1295 preparation?
No. The cited 2024 document is an advisory assessment with a proposal against bulks-list inclusion, not a product approval or a current legal-status determination.
Primary and official sources
- Teichman et al. primary publication: accessible abstract and metadata
- PubMed PMID 16352683: official bibliographic record
- FDA: 2024 PCAC briefing on CJC-1295-related substances
Editorial evidence review: September 3, 2026. This is a source-limited editorial review, not an independent specialist review or a full-paper, protocol or product-quality audit. The abstract/metadata, selected FDA text and eight relevant FDA page images were reviewed. Research information only, not medical advice or practical-use instructions. Report a correction.