Why good embryos sometimes fail — and what hormones alone cannot fix
At Dr Ryu Natural Medicine, many patients come to us after a long and emotionally exhausting IVF journey.
They have done everything “right.” Embryo quality is good. Chromosomal screening may even be normal. Hormone levels appear optimal. Yet implantation does not occur — or pregnancies end very early.
When this happens repeatedly, the experience is often labelled “unexplained IVF failure.”
From a metabolic perspective, it is rarely unexplained.
IVF focuses on embryos — implantation depends on energy
IVF is exceptional at creating embryos.
What it cannot guarantee is whether the maternal system can receive, support, and sustain that embryo.
Implantation is not a passive event. It is one of the most energy-intensive transitions in human physiology. The endometrium must rapidly shift fuel use, oxygen handling, immune signalling, and mitochondrial output — all within a narrow implantation window.
If metabolic flexibility is impaired, this transition may simply fail to complete.
A perfect embryo cannot override a metabolically constrained environment.
The silent metabolic patterns behind IVF failure
Many women who experience IVF failure share a similar underlying profile, even if their basic tests look reassuring.
Glucose may be normal, yet insulin is already elevated. Fatty acids circulate inappropriately, creating inflammatory signals. Thyroid-driven metabolic rate is often suppressed under chronic stress. Mitochondria are forced into inefficient fuel use.
Before IVF, these patterns may be compensated.
During IVF — with hormonal stimulation, altered sleep, emotional stress, and rapid tissue growth — compensation breaks down.
IVF does not cause the metabolic problem.
It amplifies it.
Endometrial receptivity is a metabolic state
Endometrial receptivity is often discussed in structural terms: thickness, pattern, timing. These factors matter — but they sit on top of a deeper requirement.
The endometrium must be able to:
- Uptake and utilise glucose efficiently
- Maintain oxygen use without hypoxia
- Suppress excess inflammation
- Respond precisely to progesterone
All of these processes depend on cellular energy availability.
When insulin is high or fatty acids dominate fuel signalling, glucose uptake into endometrial cells is impaired. Local inflammation increases. Oxygen utilisation becomes inefficient. Progesterone signalling weakens, even when blood levels appear adequate.
The lining may look “ready,” but functionally it is not.
Why repeated IVF cycles often worsen outcomes
A common but rarely discussed pattern is declining implantation success across repeated IVF cycles.
Each cycle places additional metabolic strain on the system:
- Ovarian stimulation increases energy demand
- Hormonal manipulation alters insulin sensitivity
- Emotional stress elevates cortisol
- Recovery time between cycles is often insufficient
Without addressing the underlying metabolic load, each cycle can push the system further from flexibility and closer to rigidity.
At this point, adding more hormones or changing protocols may produce diminishing returns.
Implantation failure is often a fuel problem, not a hormone problem
Progesterone resistance is frequently cited in implantation failure. From a metabolic perspective, resistance often reflects energy insufficiency, not receptor defects.
Hormones require energy to signal effectively.
When mitochondrial output is constrained, hormonal messages arrive but cannot be acted upon.
This is why:
- Increasing progesterone does not always help
- Higher oestrogen may worsen outcomes
- “Optimal” hormone levels fail to translate into pregnancy
The system lacks the metabolic bandwidth to respond.
Why metabolic preparation must happen before IVF
Once an IVF cycle begins, the opportunity to correct metabolic dysfunction is limited. Aggressive dietary changes can increase stress hormones. Calorie restriction is unsafe. Hormonal protocols lock metabolism into a narrow range by design.
Before IVF, however, the body is adaptable.
Insulin sensitivity can improve. Fat metabolism can be stabilised. Thyroid–mitochondrial coupling can recover. Inflammatory signalling can be reduced. The endometrium can regain metabolic responsiveness.
This preparatory phase is often the missing piece in “unexplained” IVF failure.
A different question to ask after IVF failure
Instead of asking:
“What went wrong with this cycle?”
A more revealing question is:
“Was the metabolic system capable of supporting implantation at all?”
When metabolic flexibility improves:
- Implantation rates often rise without changing embryos
- IVF cycles become more efficient, not more aggressive
- Pregnancy is better tolerated once achieved
- Early losses become less common
These shifts are driven by physiology, not chance.
The deeper truth about IVF success
IVF can create life.
Only a metabolically prepared system can sustain it.
IVF failure is often not a failure of embryos — it is a failure of energy availability.
This does not mean something is “wrong” with the body. It means the system is being asked to perform a task it was not metabolically prepared for.
Preparation changes that.
How Dr Ryu Natural Medicine approaches IVF differently
At Dr Ryu Natural Medicine (London, UK), we approach IVF through a metabolic and physiological lens. Rather than focusing solely on hormone targets, we assess how energy is produced, allocated, and regulated before treatment begins.
This approach is particularly valuable for:
- Repeated IVF failure
- Implantation failure
- “Good embryo, no pregnancy” cases
- IVF after gestational diabetes or metabolic stress
- IVF in women over 35 where metabolic reserve matters most
Our goal is not to replace IVF, but to make the body a more capable partner in the process.
Final thought
IVF does not bypass physiology.
It reveals it.
When metabolic flexibility is restored before treatment, IVF stops feeling like a gamble and starts behaving more like a partnership between technology and biology.
