The current estrogen patch shortage is a concrete example
This is likely because they dont see them as being effective or safe enough for commercial return, to justify the research and development costs
A study in an academic publication called (appropriately) AMINO ACIDS, demonstrated that branched-chain amino acids along with two specific amino acids, glutamine or proline, restored collagen synthesis after UV exposure

[17] 2015, Some oxidative and antioxidative parameters and their relationship with clinical symptoms in women with fibromyalgia syndrome [18] 2015, Understanding the Association of Fatigue With Other Symptoms of Fibromyalgia: Development of a Cluster Model [19] 2015, Evaluation of Antiviral Antibodies against Epstein-Barr Virus and Neurotransmitters in Patients with Fibromyalgia [20] 2015, Sleep is associated with task-negative brain activity in fibromyalgia participants with comorbid chronic insomnia [21] 2015, Cognitive performance is related to central sensitization in patients with chronic whiplash-associated disorders and fibromyalgia: a case-control study [22] 2015, Normalization of aberrant resting state functional connectivity in fibromyalgia patients following a three-month physical exercise therapy [24] Our model also suggests that drugs that specifically target the somatosensory thalamus may be effective in treating fibromyalgia

Definition and diagnostic criteria of clinical obesity [published correction appears in Lancet Diabetes Endocrinol
Ageing Solutions FAQ page states that a doctor reviews the Pre-Medical Screening questionnaire before granting access to the range of Integrative Medical Solutions for Guardian Australia, this occurred instantly and the doctors identity was not disclosed